Clinical Outcomes of Trimethoprim/Sulfamethoxazole in Critically Ill Patients with Stenotrophomonas maltophilia Bacteremia and Pneumonia Utilizing Renal Replacement Therapies

Background: The clinical outcomes of usual doses of Trimethoprim-sulfamethoxazole (TMP/SMZ) for treating S. maltophilia in critically ill patients on renal replacement therapies (RRT) have not been established. We sought to assess the clinical outcomes of TMP/SMZ in patients with sepsis utilizing RRT. Methods: A retrospective study was performed on all critically ill adult patients with S. maltophilia infections who received RRT between May 2015 and January 2022. The primary endpoint was clinical cure while the secondary endpoints were microbiologic cure, 30-day infection recurrence, and mortality. Results: Forty-five subjects met the inclusion criteria. The median age was 70.0 [interquartile range (IQR): 63.5-77] years, 57.8% were males, and the median body mass index was 25.7 [IQR: 22-30.2] kg/m2. Clinical success and failure were reported in 18 (40%) and 27 (60%) cases, respectively. There was no significant difference between the 30-day reinfection rates of both groups; however, mortality was significantly higher in the clinical failure group, involving 12 patients (44.4%), versus none in the clinical success group (p = 0.001). The median daily dose of TMP/SMZ upon continuous veno-venous hemofiltration was 1064 [IQR: 776-1380] mg in the clinical cure group vs. 768 [IQR:540-1200] mg in the clinical failure group (p = 0.035). Meanwhile, the median dose for those who received intermittent hemodialysis was 500 [IQR: 320-928] mg in the clinical success group compared to 640 [IQR: 360-1005] mg in the clinical failure group (p = 0.372). A total of 55% experienced thrombocytopenia, 42% hyperkalemia, and 2.2% neutropenia. The multivariable logistic regression analysis showed that the total daily dose at therapy initiation was the only independent factor associated with clinical success after adjusting for different variables including the body mass index [Odds ratio 1.004; 95% confidence interval: (1-1.007), p = 0.044]. Conclusions: Although the S. maltophilia isolates were reported as susceptible, TMP/SMZ with conventional doses to treat bacteremia and pneumonia in critically ill patients utilizing RRT was associated with high rates of clinical and microbiologic failure as well as with mortality. Larger outcomes and pharmacokinetics studies are needed to confirm our findings.

Racial differences in P2Y12 inhibitor responsiveness in patients undergoing neuro-endovascular procedures: A cohort from the Middle East

BACKGROUND

Data on P2Y12 inhibitors responsiveness from the middle east is scarce. We sought to investigate patient responsiveness to P2Y12 inhibitors within a cohort of major races that characterize the UAE population. The secondary objective was to assess risk factors for hyper and hypo-responsiveness in this population.

METHODS

We conducted a cross-sectional study on adults who received either clopidogrel or ticagrelor treatments and had platelet responsiveness testing before undergoing neuro-endovascular interventions at our quaternary care hospital between March 2015 and April 2019.

RESULTS

During the study period, 249 subjects met the inclusion criteria. Overall, 17.3 % were hyper-responsive and 25.7 % were hypo-responsive to P2Y12 inhibitors. When comparing between the P2Y12 inhibitors, rates of hyper-responsiveness were significantly higher to ticagrelor when compared to clopidogrel (11 versus 6 %, p = 0.02 respectively). Contrarily, hypo-responsiveness rates were significantly higher in clopidogrel treated patients compared to their ticagrelor treated counterparts (23 versus 2 %, p < .001 respectively). Patients of Middle-Eastern origin showed a significantly higher rate of hypo-responsiveness to both clopidogrel and ticagrelor when compared to other races (41.1 % and 26.7 %, P < 0.001 respectively). Asians showed the highest rates of hyper-responsiveness for both agents. Multivariate logistic regression analysis showed that proton pump inhibitors and statin combination, (OR: 6.39, 95 %CI [1.60, 25.392]), and Middle East vs. Indian subcontinent patients (OR: 4.67, 95 %CI [1.79-12.14]) were independent predictors of hypo-responsiveness to both P2Y12 inhibitors.

CONCLUSION

This study demonstrated a high rate of hypo-responsiveness to P2Y12 inhibitors in a UAE cohort of patients undergoing neuro-endovascular procedures. In addition, therapeutic responsiveness to P2Y12 inhibitors varied markedly based on the racial background. Future larger studies are needed to evaluate genetic variations that may contribute to this rate of hypo-responsiveness in our population.

The Safety and Effectiveness of Apixaban in Patients with End-Stage Kidney Disease on Dialysis: A Retrospective Observational Study

Background: Apixaban has been increasingly utilized for various FDA-approved indications, including stroke prevention and venous thromboembolism (VTE) treatment in patients with end stage kidney disease (ESKD) on hemodialysis. However, the safety and efficacy of its use in this population is not well established. Hence, the purpose of this study is to evaluate the safety and effectiveness of apixaban by examining outcomes in this population. Methods: This was a retrospective observational study that involved adults with ESKD who were on hemodialysis and prescribed apixaban from our hospital's outpatient pharmacy between 1 May 2015, and 31 March 2022. Demographics, apixaban indications, dose appropriateness, concomitant antiplatelet use, and comorbidities data were collected. Bleeding and thromboembolic events were also collected. Results: Sixty-six patients fulfilled the inclusion criteria, 50% of them males. Median age was 71 (63.5-82) years, and the median BMI 28.2 (59.5-86.25) kg/m2. The median follow-up time was 5 (1.9-12.3) months. Concomitant antiplatelet use (39.4%) and high medication adherence (84.8%) were observed. During follow-up, major bleeding events occurred in 15.2% of cases, with minor bleeding being more common (36.4%), and VTE and stroke events occurred in 4.5% of cases; appropriate dosing was prevalent (62.1%), and there was an overall all-cause mortality rate of 34.8%. Most patients received a 2.5 mg BID apixaban dose (56.1%), including both NVAF and VTE groups. Notably, the multivariate logistic regression analysis indicated that weight, and daily dose were insignificant predictors of bleeding events (p = 0.104, 0.591), however, the BMI was the main independent risk factor for bleeding in this population [OR = 0.9, 95% CI: 0.8-0.99; p = 0.023]. Conclusions: Our analysis of apixaban-treated ESKD patients highlights that the risk of bleeding is significant, and BMI was the main independent risk factor. A larger prospective study is needed to confirm our findings.

Terahertz Detection by Asymmetric Dual Grating Gate Bilayer Graphene FETs with Integrated Bowtie Antenna

An asymmetric dual-grating gate bilayer graphene-based field effect transistor (ADGG-GFET) with an integrated bowtie antenna was fabricated and its response as a Terahertz (THz) detector was experimentally investigated. The device was cooled down to 4.5 K, and excited at different frequencies (0.15, 0.3 and 0.6 THz) using a THz solid-state source. The integration of the bowtie antenna allowed to obtain a substantial increase in the photocurrent response (up to 8 nA) of the device at the three studied frequencies as compared to similar transistors lacking the integrated antenna (1 nA). The photocurrent increase was observed for all the studied values of the bias voltage applied to both the top and back gates. Besides the action of the antenna that helps the coupling of THz radiation to the transistor channel, the observed enhancement by nearly one order of magnitude of the photoresponse is also related to the modulation of the hole and electron concentration profiles inside the transistor channel by the bias voltages imposed to the top and back gates. The creation of local n and p regions leads to the formation of homojuctions (np, pn or pp+) along the channel that strongly affects the overall photoresponse of the detector. Additionally, the bias of both back and top gates could induce an opening of the gap of the bilayer graphene channel that would also contribute to the photocurrent.

The prevalence of cardiorenal anemia syndrome among patients with heart failure and its association with all-cause hospitalizations: a retrospective single-center study from the Middle East

Background and aim

Little is known about the burden of cardiorenal syndrome (CRS) and cardiorenal anemia syndrome (CRAS) in the Middle East Region. Furthermore, whether the occurrence rates of CRAS differ across heart failure (HF) phenotypes is not widely investigated. We aimed to examine the prevalence of CRS and CRAS in patients with HF, compare characteristics of patients with CRAS-HFrEF vs. CRAS-HFpEF, and investigate anemia association with 1-year all-cause hospitalizations.

Methods

HF patients who visited a multidisciplinary HF clinic at a single center between 10-2015 and 06-2022 (n = 968) were retrospectively included. Differences in rates of CRAS prevalence, and patients' characteristics of those with CRAS-HFrEF vs. CRAS-HFpEF were determined using appropriate testing methods. Generalized estimating equation (GEE) models were used to determine if anemia was associated with higher rates of hospitalization.

Results

CRS was prevalent in 34.4% of subjects, while 25.3% had CRAS. CRAS prevalence rates among patients with HFpEF vs. HFrEF were comparable (27.2% vs. 24.2%, p = 0.3). Compared to patients with HFrEF-CRAS, those with HFpEF-CRAS were more likely females (p < 0.001), had a higher burden of hypertension (p = 0.01), and lower hemoglobin (p = 0.02). In an adjusted GEE model, anemia was associated with an average increase of 1.8 admissions in CRS patients (p = 0.015).

Conclusion

In patients with HF, 1 in 3 patients presented with CRS, and 1 in 4 patients had CRAS. The prevalence of CRAS was comparable among those HFpEF and HFrEF. Anemia was associated with an increased rate of 1-year all-cause hospitalization in CRS patients.

Clinical outcomes of ceftolozane-tazobactam dosing in patients with sepsis undergoing renal replacement therapies

Ceftolozane-tazobactam (C/T) recommended dosing in patients undergoing renal replacement therapies (RRT) is lacking evidence. The objective of this study was to evaluate the clinical outcomes of C/T dosing in patients on RRT.

MATERIALS AND METHODS

A retrospective descriptive study conducted at our institution between May 1, 2017, and March 15, 2022. The primary endpoint was to determine the clinical cure for patients who received C/T for documented infection while on RRT. The secondary endpoints were the microbiologic cure, 30-day infection recurrence, and 30-day crude mortality.

RESULTS

Of the 27 patients who met the inclusion criteria, 17 (63%) were males, median age was 69 (62 - 82) years, and weight 67 (57 - 79) kg. The majority of patients had pneumonia 19 (70.4%) followed by bacteremia 5 (18.5%). Multidrug resistant Pseudomonas spp. was the causative organism of infection in 22 subjects (81.5%). Clinical cure was achieved in 17 subjects (63%). Of the 14 subjects who had their culture repeated, 10 (71.4%) patients had microbiologic cure vs. 4 (28.5%) patients who had a microbiologic failure (p = 0.327). 30-day infection recurrence occurred in 6 (35.3%) patients of the clinical cure group and 2 (20%) patients in the clinical failure group (p = 0.362), while mortality occurred in 5 (29.4%) subjects vs. 7 (70%) in both groups, respectively (p = 0.049). The most frequently used doses of C/T were 1.5 g IV q8h while undergoing continuous venovenous hemodiafiltration and 0.75 g IV q8h while undergoing hemodialysis (p = 0.209). The median duration of therapy was 9 (4.5 - 13) days in the clinically cured group vs. 5 (3.75 - 5.5) days in those who had clinical failure (p = 0.038). There was no adverse event reported using these doses during the study period.

CONCLUSION

The used doses of C/T in this study were higher than those approved by the U.S. FDA, while clinical success is uncertain. Larger outcomes and pharmacokinetics studies are needed to establish effective dosing and therapy duration.

Sustaining Life versus Altering Life-Saving Drugs: Insights to Explain the Paradoxical Effect of Extracorporeal Membrane Oxygenation on Drugs

There has been a substantial increase in the use of extracorporeal membrane oxygenation (ECMO) support in critically ill adults. Understanding the complex changes that could affect drugs' pharmacokinetics (PK) and pharmacodynamics (PD) is of suitable need. Therefore, critically ill patients on ECMO represent a challenging clinical situation to manage pharmacotherapy. Thus, clinicians' ability to predict PK and PD alterations within this complex clinical context is fundamental to ensure further optimal and, sometimes, individualized therapeutic plans that balance clinical outcomes with the minimum drug adverse events. Although ECMO remains an irreplaceable extracorporeal technology, and despite the resurgence in its use for respiratory and cardiac failures, especially in the era of the COVID-19 pandemic, scarce data exist on both its effect on the most commonly used drugs and their relative management to achieve the best therapeutic outcomes. The goal of this review is to provide key information about some evidence-based PK alterations of the drugs used in an ECMO setting and their monitoring.

Microbiologic outcomes of ceftazidime-avibactam dosing in patients with sepsis utilizing renal replacement therapies

INTRODUCTION

The suggested dose of ceftazidime-avibactam (CEF/AVI) in patient with multidrug resistant organisms and utilizing renal replacement therapies (RRTs) is not validated in clinical studies. The objective of this study was to evaluate the microbiologic cure of bacteremia and pneumonia using the recommended CEF/AVI dosing in patients utilizing RRT.

METHODS

A retrospective observational study conducted at our institution between September 15, 2018 and March 15, 2022. The primary end point was to determine the microbiologic cure. The secondary end points were the clinical cure, 30-day recurrence, 30-day all cause mortality.

RESULTS

Fifty-six patients met the inclusion criteria, 36 (64.3%) were males, the median age was 69 (59.5-79.3) years, and the median weight was 69 (60-83.8) kg. Pneumonia represented 34 (60.7%) of infections. Microbiologic cure was achieved in 32 (57%) subjects. However, clinical cure was achieved in 23 (71.9%) patients in the microbiologic cure group versus 12 (50%) in the microbiologic failure group (p = 0.094). The 30-day recurrence occurred in 2 (6.3%) patients in the microbiologic cure group versus 3 (12.5%) in the microbiologic failure group (p = 0.673). Further, the 30-day all-cause mortality was 18 (56.3%) versus 10 (41.7%) in both groups respectively (p = 0.28). The most used dose in patients utilizing continuous veno-venous hemofiltration (CVVH) was 1.25 g q8h, while the dose was 1.25 g q24h in those who utilized intermittent hemodialysis (IHD). The multivariate logistic regression indicated that bacteremia (OR 41.5 [3.77-46]), Enterobacterales (OR 5.4 [1.04-27.9]), and the drug daily dose (OR 2.33 [1.15-4.72]) were independently associated with microbiologic cure.

CONCLUSION

Microbiologic cure of ceftazidime-avibactam in patient utilizing CVVH and IHD is dependent on bacteremia diagnosis, the drug daily dose, and bacterial species. These findings need to be replicated in a larger prospective study, with no recommendations in those utilizing RRT.

Sex differences in cardiac remodeling post myocardial infarction with acute cigarette smoking

Background

Whether cigarette smoking affects the heart post-myocardial infarction (MI) in a sex-dependent way remains controversial. Using a mouse model, we investigated cardiac remodeling under the influence of acute cigarette smoke (CS) exposure following ischemic injury in both sexes.

Methods

Ten cigarettes were smoked twice daily for 2 weeks followed by MI and then 1 additional week post permanent LAD ligation. Cardiac function, histology, and infarct size were assessed, and inflammatory markers quantified by RT–PCR. Statistical comparisons were performed using an unpaired t test or ANOVA followed by Tukey post hoc test.

Results

We observed that cigarette smoking exacerbated both left and right ventricular remodeling only in males at an early stage of post-MI. Females did not display a significant structural and/or functional alteration within 7 days of cardiac remodeling post-MI upon CS exposure. Worsened right ventricular remodeling in males was independent of pulmonary congestion. CS-exposed males exhibited enhanced increases in left ventricular end systolic and diastolic volumes, as well as reductions in ejection fraction and fractional area changes of left ventricular base. At day 7, infarct size was increased by cigarette smoking in males only, which was accompanied by enhanced collagen deposition in both the infarcted and peri-infarcted areas. Both IL-6 and TNF-α mRNA expression significantly increased in CS-exposed MI male group only at day 7 post-MI suggestive of prolonged inflammation.

Conclusions

These findings indicate that CS exposure worsens the progression of cardiac remodeling post-MI in male sex in a significant manner compared to female sex at least at early stages.

Tocilizumab and COVID-19: Timing of Administration and Efficacy

Elevated concentrations of interleukin-6 have been demonstrated to be an important key factor in COVID-19 host immune impairment. It represents an important prognostic factor of harm associated with COVID-19 infection by stimulating a vigorous proinflammatory response, leading to the so-called “cytokine storm”. Therefore, immunomodulatory interventions targeting interleukin-6 receptor antagonism have been investigated as potential treatments to counterbalance the host immune dysregulation and to support the advantageous effects of corticosteroids. Tocilizumab is a recombinant humanized monoclonal antibody that has gained much interest during the COVID-19 pandemic as an interleukin-6 receptor antagonist. Various early observational studies have reported beneficial effects of tocilizumab. Moreover, consequent randomized controlled trials have subsequently shown significant positive results about tocilizumab efficacy and safety, focusing on outcomes like mortality, risk of intensive care unit admission, and the need for mechanical ventilation, while others presented conflicting findings. In this review, we first described the pathophysiology of COVID-19 infection while highlighting the role of interleukin-6. Furthermore, we also discussed the non-conclusive evidence about tocilizumab to be used as the standard of care therapy for all patients with COVID-19 pneumonia, as well as its beneficial effects in selected patients.

Abstract P173: The Impact Of Cigarette Smoking-oral Contraceptive Combination On Cardiac Remodeling In Premenopausal Female Mice

Introduction: Tobacco smoke is a major risk factor for coronary artery diseases (CAD) and chronic tobacco smoking (CS) increase the risk of CAD by 2 to 4 folds. CS effect on cardiac homeostasis has never been evaluated in premenopausal females taking oral contraceptive (OC). This study investigates CS effect on cardiac remodeling in female mice in the presence or absence of Ethinyl Estradiol (EE).

Methods: Blood pressure and echocardiography were recorded for female C57BL/6J mice on EE, EE-CS, vehicle, and vehicle-CS at baseline and after 8-weeks of exposure. Cardiac inflammatory cytokines and oxidative stress markers were evaluated by real time PCR and western blots. Interstitial collagen deposition was assessed by Masson Trichrome staining.

Results: Eight weeks of EE-CS treated mice showed no effect on BP but significant adverse structural and functional cardiac effects, represented by increased systolic (0.981 ± 0.035 N=11 (p<0.0332)) and diastolic (1.450 ± 0.037 N=11 (p<0.0002)) areas when compared to the vehicle and EE groups, along with increased systolic (1.981 ± 0.109 N=11 (p<0.033)) and diastolic ( 3.911 ± 0.159 N=11 (p<0.033)) volumes when compared to all groups. Functional changes were accompanied with a decreased fractional shortening (9.194 ± 1.006 N=11 (p<0.033)) when compared to vehicle and EE groups with no changes in ejection fraction parameter. Moreover EE-CS treatment significantly increased NOX-4 expression (2.297 ± 0.643 N=5 (p<0.033)) when compared to EE treatment alone, along with an increased pro-inflammatory profile including IL-1β (0.750 ±0.171N=5 (p<0.033)) and IL-4 (4.110 ± 0.623 N= 5 (p<0.002)) when compared to all groups, and IL-6 (3.045±0.910 N=5 (p<0.002)) and IL-13 (2.686 ± 0.648 N=5 (p<0.033)) when compared to vehicle-CS group. Morphologically, EE-CS exhibited a significant increase in interstitial fibrosis (1.186± 0.020 N=5, 3.2285 ± 0.683 N=5, (p<0.033)) when compared to the vehicle-CS group.

Conclusion: This study provides clear evidence that CS-exposed premenopausal female mice on OC regimen exhibited significant adverse cardiac events that could be classified under cardiac dysfunction with preserved ejection fraction. Additional experiments are warranted to further elaborate on these findings.

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

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

Tobacco cigarette smoking exacerbates aortic calcification in an early stage of myocardial infarction in a female mouse model

Despite increased social awareness, marketing restraints, tobacco taxation, and available smoking cessation rehab programs, active and passive smoking remain a worldwide challenging epidemic and a key risk factor for cardiovascular diseases development. Although cardiovascular (CV) protection is more pronounced in women than in men due to estrogenic effects, tobacco cigarette smoking exposure seems to alter this protection by modulating estrogen actions via undefined mechanisms. Premenopausal cigarette smoking women are at higher risk of adverse CV effects than non-smokers. In this study, we investigated the impact of cigarette smoking on early CV injury after myocardial infarction (MI) in non-menopausal female mice. Aortic arch calcification, fibrosis, reactive oxygen species, and gene expression of inflammatory and calcification genes were exaggerated in mice exposed to cigarette smoke (CS). These findings suggest that aortic injury following MI, characterized by vascular smooth muscle cells transdifferentiation, calcification, inflammation, and collagen deposition but not cardiac dysfunction is exacerbated with CS exposure. The novel findings of this study highlight the importance of aortic injury on short and long-term prognosis in CS-exposed MI females. Linking those findings to estrogen alteration is probable and entails investigation.

Mercurial hospital waste: management, becoming and recommendations

INTRODUCTION AND PURPOSE

In hospitals, the use of medical instruments and products containing mercury and the management of mercury waste (MW) collected are regulated in developed countries. In Tunisia, MW end up in landfill and no strategy has so far been adopted. The objective of this study was to quantify MW in two university hospitals in Tunis and to indicate the elimination pathways used and to propose certain recommendations.

METHODS

This was a descriptive retrospective study conducted from February to August 2016 and quantifying the MWs from medical products and instruments used by two university hospitals in Tunis during 2015. Semi-structured interviews and focus groups enabled the collection of informations on MW management methods for these products and instruments and their waste and to identify the weaknesses of this management.

RESULTS

In 2015, 2,443 mercury thermometers were used by Habib Thameur hospital (HHT) and 7,439 by La Rabta hospital (HLR), releasing 19,764 g of mercury. For dental amalgams, 1,440 g were used at HHT. Their residues (320.4 g) were stored in the original capsules. At HLR, 1,320 g were used but residues, estimated at one-third of the total amount (440g), were discharged into the cuspidor. The total amount released from the amalgams was 380.2g, knowing that half of the volume was mercury. The broken tensiometers (26 at HHT and 113 at HLR) released 183.5g of mercury, the roasted fluorescent lamps (1,627 at HHT and 1,722 at the HLR) 167.4g, Harris Hematoxylin (15 liters at HHT and 18 liters at HLR) 82.5g and used batteries (1,258 at the HHT and 914 at the HLR) 54,3g. In total, with the exception of mercury vapors, the amount of mercury released in 2015 at the two hospitals was approximately 20,632 g. These MW have borrowed the household waste stream (51% of HHT MW and 47% of HLR MW), waste from infectious care activities (47% HHT and 46% of the HLR MW), electrical and electronic waste (1% of HHT and HLR MW), and sewage (1% of HHT MW and 6% of the HLR MW).

CONCLUSION

The main supplier of hospital MW is the mercury thermometer (95.8%). The managerial authorities would benefit from the promulgation of a regulatory framework, like the European law of 1998, prohibiting their use on a territorial scale and, by subsidies, replace them with electronic thermometers.

Functional, Cellular, and Molecular Remodeling of the Heart under Influence of Oxidative Cigarette Tobacco Smoke

Passive and active chronic cigarette smoking (CS) remains an international epidemic and a key risk factor for cardiovascular disease (CVD) development. CS-induced cardiac damage is divided into two major and interchangeable mechanisms: (1) direct adverse effects on the myocardium causing smoking cardiomyopathy and (2) indirect effects on the myocardium by fueling comorbidities such as atherosclerotic syndromes and hypertension that eventually damage and remodel the heart. To date, our understanding of cardiac remodeling following acute and chronic smoking exposure is not well elucidated. This manuscript presents for the first time the RIMD (oxidative stress (R), inflammation (I), metabolic impairment (M), and cell death (D)) detrimental cycle concept as a major player in CS-induced CVD risks and direct cardiac injury. Breakthroughs and latest findings in the field with respect to structural, functional, cellular, and molecular cardiac remodeling following chronic smoking exposure are summarized. This review also touches the genetics/epigenetics of smoking as well as the smoker's paradox and highlights the most currently prominent pharmacological venues to mitigate CS-induced adverse cardiac remodeling.

Impact of pathology theses supported at the medical university of Tunis (2000-2010)

BACKGROUND

The thesis is an research work wish must submit to rigorous scientific criteria. However, this research effort remains inaccessible to international scientific communities. The aims of this study were to determinate the publication rates in indexed journals and factors affecting publication.

METHODS

This was a retrospective descriptive study of pathology theses listed in the theses catalog of the library medical university of Tunis whose theses were supported between 2000-2010. Publication had been searched in databases "Pub Med". The number of citations received by each published thesis was recorded in www. Scopus.com.

RESULTS

Our study concerned 189 theses. Thirty five original articles were derived from 33 theses (17.5%). Eleven medical indexed journals have made the support of articles, dominated by generalist journal (La Tunisie Médicale: 68.6%), specialist journals (Annales de Pathologies, Pathology, Ultrastructural Pathology: 11.4%). The number of article citations had an average of 1. Theses with informative title had been more publication (p=0.005). Theses with structured introduction had been more publication (p=0.002).

CONCLUSION

Publication rate of pathology theses in indexed journals are relatively low. This publication rate could be improved by the organization of seminars and workshops on writing articles from theses or by the improvement of these articles in national competitions.

Critical study of pathology theses supported at the medical university of Tunis (2000-2010)

BACKGROUND

Medical writing is a coded language; its purpose is to convey a scientific message. In pathology, specialty involving the study of cell and tissue, quantitative and qualitative production of medical doctoral theses and their thematic focus has not been studied. The aim of this study was to analyze the pathology theses on the level of form, the background and methodology.

METHODS

Descriptive retrospective study of medical doctoral theses in the specialty "Pathology", listed in the catalog of theses of the library of the Faculty of Medicine of Tunis and supported between 2000 and 2010. Each thesis has been subject of a direct reading, systematic and thorough.

RESULTS

The study involved 189 pathology theses. The average overall productivity per academic pathologist was 5.5 theses. Gastrointestinal pathology was the most studied theme (24.9%). Tumor pathology was addressed in 74.1% of the theses. The IMRAD structure was respected in 57.7% of theses; by assistant professor than by associate professor and professor (p = 0.005). The summary was structured in 88.3% of theses, comparably with the grade of the thesis director (p = 0.5) and with the grade of PhD student (p = 0.08). The transcript of references did not meet the recommendations of Vancouver in 87.8% of theses and irrespective of the rank of director of thesis (p = 0.2).

CONCLUSION

The pathology theses presented some shortcomings, particularly in the quality of medical writing. To remedy this problem, our faculty should increase efforts to improve the quality of scientific work, in order to have a better view of medical research in Tunisia.

Effects of methanol extracts from roots, leaves, and fruits of the Lebanese strawberry tree (Arbutus andrachne) on cardiac function together with their antioxidant activity

CONTEXT

Several plant-derived natural products have been used in clinical phase for applications in neurological, cardiovascular, and inflammatory diseases. Arbutus andrachne L. (Ericacea) is an evergreen shrub native to the Mediterranean region. Traditionally, the fruits and leaves of Arbutus tree are well known and used as antiseptics, diuretics, blood tonic, and laxatives.

OBJECTIVE

Data regarding the biological effects of compounds derived from the Lebanese Arbutus andrachne are not available. In the present work, we studied the antioxidant activity of methanol extracts of leaves, fruits, and roots of the plant against electrolysis; together with their effects on the cardiodynamics of isolated perfused rabbit hearts.

MATERIALS AND METHODS

In vitro electrolysis of the different root, leaves, and fruits methanol extracts was evaluated by the amount of free radicals that has been reduced by increasing the concentration of root extracts ranging from 0.5 to 2 mg after 1, 2, 3, and 4 min. Left ventricular pressure (LVP), heart rate (HR), and coronary flow (CR) were investigated in isolated rabbit heart after administration of 0.5, 1, 2, and 2 mg of each methanol extracts plotted against time (0, 0.5, 1.5, 5, and 10 min), according to the Langendorff method. Lipid peroxidation study was performed by the colorimetric method on myocard tissue after incubation with 500 μl of the different methanol extracts. The amount of MDA was determined at 500 nm absorbance after 5 min incubation.

RESULTS

Among the different methanol extracts, the roots showed the highest in vitro antioxidant activity, particularly observed at concentration of 2 mg which completely inhibits free radical generation after 4 min. LVP decreases by 32% at the dose of 2 mg of root extracts after 5 min. No significant effect was observed by the three tested extracts on the heart rate. The three methanol extracts did not show any significant effect on the coronary flow. Moreover, the roots show an increase in the coronary flow at a concentration of 1 and 2 mg/ml during 1 min. Electrolysis on heart tissue treated with the roots extracts shows a decrease in the MDA level from 70.51 ± 6.71 to 48.58 ± 4.15 nmole/g of tissue.

DISCUSSION AND CONCLUSION

Methanol extracts of the roots possess antihypertensive effect that may result from its ability to decrease the LVP together with its protective role by inhibiting free radical generation and significantly decreasing the MDA level of heart tissue.