Abstract 278: Protective Effects of Niacin in a Murine Model of Abdominal Aortic Aneurysms

Introduction.

Abdominal aortic aneurysms (AAAs) are common among the aging population, yet there is no effective pharmacotherapy. Neutrophils play a key role in the pathogenesis of AAA, by triggering inflammation, oxidative stress, matrix degradation and smooth muscle cell (SMC) death. Niacin, a vitamin with beneficial cardiovascular effects, was shown previously to reduce vascular neutrophil infiltration, MPO accumulation, and HOCl-induced endothelial dysfunction in a rabbit perivascular injury model.

Hypothesis

We hypothesized that niacin would have beneficial effects to prevent AAA in a mouse model.

Methods

LDL null mice were infused with angiotensin II (1000 ng/kg/min) for 14 days to induce AAA with (n=27) or without (n=18) 0.3% supplemental niacin in the drinking water. One group (n=6) received the DP1 receptor antagonist, laropiprant, in addition to niacin. We also investigated the effects of niacin on MMP release in a human neutrophil cell line (HL-60) and on viability of a murine SMC line (MOVAS-1) challenged with 100μM H 2 O 2 .

Results

Niacin decreased the rate of AAA formation as compared to untreated control mice, 26% vs. 83%, respectively. In mice that survived the complete 14 day treatment period and did not die due to a ruptured AAA, the mean suprarenal aorta diameters were 1.20 mm (SEM 0.09) in niacin treated mice vs. 1.68 mm (SEM 0.12) in the control group, representing a niacin treatment effect of a 29% diameter decrease (p<0.5). Laropiprant did not have an effect on AAA formation, however did increase the blood pressure moderately. In HL-60 cells stimulated with TNF-α, niacin (10mM) decreased MMP 9 activity by 88% but had no effect on cell viability. In MOVAS-1 cells exposed to hydrogen peroxide, 10mM niacin had a protective effect, reducing cell death at 12 hours (50% dead cells with niacin + H 2 O 2 vs. 93% dead cells with hydrogen peroxide alone, p=0.02).

Conclusions

We conclude that niacin decreases the incidence of AAA and demonstrates pleiotropic effects on neutrophils and SMCs that may underlie its already known beneficial lipid modifying mechanisms. These novel findings suggest that niacin might be a safe, effective and inexpensive medical therapy for AAA.

[Stent graft of the thoracic aorta]

Considering the demographic changes in our society and the proliferation of imaging-based improved diagnostics, both acute and chronic aortic diseases attract increasing attention and require dedicated care. Cardiac as well as vascular surgery used to represent the gold standards for therapeutic management of pathologies of the ascending aorta and the arch; however, the technological evolution of endoluminal strategies has had a serious impact on the treatment of the descending aorta, the aortic arch in combination with vascular debranching or bypass, and in selected cases even on managing pathologies of the ascending aorta. Although several case series and meta-analyses of published observations hint towards superiority of endografting in comparison to open surgical repair, the affected usually multimorbid patients with highly complex aortic disease should be subjected to an individual evaluation by a team of cardiologists, cardiac and vascular surgeons as well as imaging specialists; a dedicated individualized treatment concept in highly experienced centers of excellence is likely to provide the best results for such challenging patients.

CD14 directs adventitial macrophage precursor recruitment: role in early abdominal aortic aneurysm formation

Background

Recruitment of macrophage precursors to the adventitia plays a key role in the pathogenesis of abdominal aortic aneurysms (AAAs), but molecular mechanisms remain undefined. The innate immune signaling molecule CD14 was reported to be upregulated in adventitial macrophages in a murine model of AAA and in monocytes cocultured with aortic adventitial fibroblasts (AoAf) in vitro, concurrent with increased interleukin‐6 (IL‐6) expression. We hypothesized that CD14 plays a crucial role in adventitial macrophage precursor recruitment early during AAA formation.

Methods and Results

CD14^−/− mice were resistant to AAA formation induced by 2 different AAA induction models: aortic elastase infusion and systemic angiotensin II (AngII) infusion. CD14 gene deletion led to reduced aortic macrophage infiltration and diminished elastin degradation. Adventitial monocyte binding to AngII‐infused aorta in vitro was dependent on CD14, and incubation of human acute monocytic leukemia cell line‐1 (THP‐1) monocytes with IL‐6 or conditioned medium from perivascular adipose tissue (PVAT) upregulated CD14 expression. Conditioned medium from AoAf and PVAT induced CD14‐dependent monocyte chemotaxis, which was potentiated by IL‐6. CD14 expression in aorta and plasma CD14 levels were increased in AAA patients compared with controls.

Conclusions

These findings link CD14 innate immune signaling via a novel IL‐6 amplification loop to adventitial macrophage precursor recruitment in the pathogenesis of AAA.

Enhanced mobilization of the bone marrow-derived circulating progenitor cells by intracoronary freshly isolated bone marrow cells transplantation in patients with acute myocardial infarction

Autologous bone marrow cell transplantation (BMCs-Tx) is a promising novel option for treatment of cardiovascular disease. We analysed in a randomized controlled study the influence of the intracoronary autologous freshly isolated BMCs-Tx on the mobilization of bone marrow–derived circulating progenitor cells (BM-CPCs) in patients with acute myocardial infarction (AMI). Sixty-two patients with AMI were randomized to either freshly isolated BMCs-Tx or to a control group without cell therapy. Peripheral blood (PB) concentrations of CD34/45⁺- and CD133/45⁺-circulating progenitor cells were measured by flow cytometry in 42 AMI patients with cell therapy as well as in 20 AMI patients without cell therapy as a control group on days 1, 3, 5, 7, 8 and 3, 6 as well as 12 months after AMI. Global ejection fraction (EF) and the size of infarct area were determined by left ventriculography. We observed in patients with freshly isolated BMCs-Tx at 3 and 12 months follow up a significant reduction of infarct size and increase of global EF as well as infarct wall movement velocity. The mobilization of CD34/45⁺ and CD133/45⁺ BM-CPCs significantly increased with a peak on day 7 as compared to baseline after AMI in both groups (CD34/45⁺: P < 0.001, CD133/45⁺: P < 0.001). Moreover, this significant mobilization of BM-CPCs existed 3, 6 and 12 months after cell therapy compared to day 1 after AMI. In control group, there were no significant differences of CD34/45⁺ and CD133/45⁺ BM-CPCs mobilization between day 1 and 3, 6 and 12 months after AMI. Intracoronary transplantation of autologous freshly isolated BMCs by use of point of care system in patients with AMI may enhance and prolong the mobilization of CD34/45⁺ and CD133/45⁺ BM-CPCs in PB and this might increase the regenerative potency after AMI.

Anti-herpes virus activities of bioactive fraction and isolated pure constituent of Mallotus peltatus: an ethnomedicine from Andaman Islands

BACKGROUND

Viral infections, particularly the infections caused by herpes simplex virus (HSV), represent one of the most serious public health concerns globally because of their devastating impact. The aim of this study was to evaluate the antiviral potential of methanolic crude extract of an ethnomedicine Mallotus peltatus, its active fraction and pure compound, against HSV-1 F and HSV-2 G.

RESULT

The cytotoxicity (CC(50), the concentration of 50% cellular toxicity), antiviral effective concentration (EC(50), the concentration required to achieve 50% protection against virus-induced cytopathic effect), plaque reduction and the selectivity index (SI, the ratio of CC(50) and EC(50)) was determined. Results showed that the crude methanolic extract of M. peltatus possessed weak anti-HSV activity. In contrast, the active fraction A and isolated ursolic acid from fraction A exhibited potent antiherpesvirus activity against both HSV-1 (EC(50)= 7.8 and 5.5 μg/ml; SI = 22.3 and 20) and HSV-2 (EC(50)= 8.2 and 5.8 μg/ml, and SI = 21.2 and 18.97). The fraction A and isolated ursolic acid (10 μg/ml) inhibited plaque formation of HSV-1 and HSV-2 at more than 80% levels, with a dose dependent antiviral activity, compared to acyclovir. The time response study revealed that the anti-HSV activity of fraction A and isolated ursolic acid is highest at 2-5 h post-infection. Moreover, the time kinetics study by indirect immunofluorescence assay showed a characteristic pattern of small foci of single fluorescent cells in fraction A- treated virus infected cells at 2 h and 4 h post-infection, suggesting drug inhibited viral dissemination. Further, the PCR study with infected cell cultures treated with fraction A and isolated ursolic acid at various time intervals, failed to show amplification at 48-72 h, like acyclovir treated HSV-infected cells. Moreover, fraction A or isolated ursolic acid showed no interaction in combination with acyclovir.

CONCLUSION

This study revealed that bioactive fraction A and isolated ursolic acid of M. peltatus has good anti-HSV activity, probably by inhibiting the early stage of multiplication (post-infection of 0-5 h), with SI value of 20, suggesting its potential use as anti-HSV agents.

Surface and intracardiac ECG for discriminating conduction disorders after CoreValve implantation

Background

Transcatheter aortic valve implantation (TAVI) has been developed to minimize operative morbidity and mortality in high-risk symptomatic patients unfit for open surgery. With the proximity of the aortic valve annulus to the conduction system there is, however, an unknown risk of conduction disturbances necessitating monitoring and often cardiac pacing.

Materials and methods

We enrolled 50 consecutive patients from January 2007 to 2008 in our prospective evaluation of conduction disturbances measured by surface and intracardiac ECG recordings. Baseline parameters, procedural characteristics as well as twelve-lead surface ECG and intracardiac conduction times were revealed pre-interventionally, after TAVI and at 7-day follow-up.

Results

TAVI was performed successfully in all patients. During 7 days of follow-up the rate for first-degree AV block raised from 14% at baseline to 44% at day 7 (p < 0.001), while rates for type II second- and third-degree were 0 versus 8% (p < 0.001) and 0 versus 12% (p < 0.001), respectively. Similarly, the prevalence of new left bundle branch block (LBBB) rose from 2 to 54% (p < 0.001). Intracardiac measurements revealed a prolongation of both AH and HV interval from 123.7 ± 41.6 to 136.6 ± 40.5 ms (p < 0.001) and from 54.8 ± 11.7 to 71.4 ± 20.0 ms (p < 0.001), respectively. Pacemaker implantation at a mean follow-up of 4.8 ± 1.2 days was subsequently performed in 23 patients (46%) due to complete AV block (12%) and type II second-degree AV block (8%) while another 13 patients (26%) received a pacemaker for the combination of new LBBB with marked HV prolongation. The high rate of first-degree AV block was primarily driven by an increase in HV interval.

Conclusion

Cardiac conduction disturbances were common in the early experience with CoreValve implantation necessitating close surveillance for at least 1 week.

Ventricular tachycardia and sudden death after primary PCI-reperfusion therapy: impact on primary prevention of sudden cardiac death

BACKGROUND

Current approaches to coronary artery disease (CAD) and acute myocardial infarction (MI) may not be well represented in most primary prevention trials of sudden cardiac death (SCD).

METHODS

The contemporary and ongoing registry of the Rostock infarction network (Drip & Ship) represents a well-defined cohort of patients subjected to percutaneous coronary intervention (PCI) for ST-elevation infarction (STEMI) and served as the database for both candidates for an ICD for primary prevention of SCD and for sudden death (SCD) or ventricular tachycardia (VT) during follow-up.

RESULTS

A total of 855 consecutive patients were treated with PCI for STEMI or NSTEMI in the region of Rostock (Germany) between 2001 and 2004. While all cause mortality was still 17.2%, the SCD rate was low at 1.3% during 728 ± 366 days of follow-up. Within that time 85 patients (9.9%) developed an indication for ICD therapy due to an impaired LV function (LVEF ≤ 35%) and heart failure. Univariate predictors of an ICD indication were delayed reperfusion (p = 0.001), a high creatine kinase (CK) max (p = 0.009), a persistent wide QRS complex (p = 0.001), previous cerebrovascular events (p = 0.033), and chronic renal failure (p = 0. 001). However, only 16.5% of these patients qualifying for an ICD actually received an ICD; nevertheless, the actual SCD rate was only 3.5%, while 5.4% (46 patients) suffered VTs or ventricular fibrillation (VF). The SCD/VT rate in the entire infarct population was associated with time to reperfusion (0.032), left bundle-branch block (0.002), a longer history of CAD (0.032), and VT during follow-up.

CONCLUSION

While mortality in patients with STEMI is still alarming even with PCI, the risk of SCD may be considerably decreased even in patients with an LVEF below 35%. With the current approach to primary prevention of sudden cardiac death, approximately 10% of postinfarction patients qualify for ICD therapy; however this may only reach a quarter of patients prone to SCD.

Dengue: A Clinicohaematological Profile

BACKGROUND

Fifty cases of fever, clinically suspected to be dengue were studied.

METHODS

Complete clinical, haematological evaluation and IgM capture assay was done.

RESULT

54% of patients clinically suspected to have dengue were positive for IgM antibodies by enzyme-linked immunosorbent assay (ELISA). The commonest clinical feature was fever with rash (85%). Thrombocytopenia was seen in 19% of patients only. One patient died of dengue shock syndrome (DSS).

CONCLUSION

Out of the 27 cases of seropositive dengue there was one death due to dengue shock syndrome. Thrombocytopenia may not always be a feature of dengue.

A study on habits of tobacco use among medical and non-medical students of Kolkata

BACKGROUND

Age-old practice "using tobacco" is a well known major global concern as it victimizes all its lovers by a host of chronic noncommunicable diseases including cancer; all develop very slowly and silently, and can cause premature death.

OBJECTIVES

To assess the pattern of tobacco use among the medical and nonmedical college students.

MATERIALS AND METHODS

A cross-sectional descriptive study was carried out in Kolkata collecting anonymous data from 515 medical and 349 nonmedical college students of two medical and two general colleges, selected randomly.

RESULT

Overall prevalence of tobacco use (18.3% vs 43.6%) and smoking (14.9% vs 40.7%) were significantly less in medical subjects, both across the sex and years of study. Lower rate of tobacco adoption at college level, higher quitting rate, correct knowledge regarding uselessness of filter attached with cigarette, and ill-effects of tobacco consumption were observed among medical participants. More nonmedical subjects were increasingly smoking compared to medical students. Filter-tipped cigarette was the top choice, and smoking was more prevalent mode of use among the nonmedical participants, most (62.3%) of whom were mild users. Curiosity was the top influencing factor for the initiation of tobacco use and two-third users wanted to quit.

CONCLUSION

Although the mortal habits was comparatively less among medical students, the medical environment seemed to fail to curb the dreadful practice totally. Thereby it can be recommended that active behavior-changing communication is required for all sections of the society to tear out the social root of the problem instead of unimpressive vague health warnings in vogue.

[Coronary intervention - which indications are controversial?]

Actually, the further development of surgical and interventional techniques enables the treatment of complex coronary artery disease of severely ill patients. Due to this development there is a growing spectrum of possible indications for the interventional technique. Since SYNTAX trial, the individual risk stratification and discussion of possible strategies in interdisciplinar meetings is of utmost importance again. Risk stratification should contain patients history, as well as objective findings like extent of coronary artery disease, left ventricular function, pathological stress tests and patients comorbidities. Today, controversial indications up until a short time ago were possible indications for interventional techniques like demonstrated in recent trials and registries. The most discussed controversial indications were interventions at multivessel-disease with drug-eluting stents (DES), left-main stem and chronic total occlusions.

[Use of diuretics in acute decompensated heart failure]

Patients with acute heart failure usually present with dyspnoe and edema secondary to elevated intracardiac filling pressure resulting from volume overload. Despite significant progress in understanding heart failure, the treatment strategy for acute heart failure did not change in the same way. Diuretics, especially loop diuretics, are the most common therapy used in this setting. Intravenous diuretics act acutely by exerting a modest vasodilatory response and chronically by reducing circulating blood volume. Despite near universal use of diuretics in patients hospitalized with acute heart failure, nearly half of these patients are discharged from hospital without weight loss. This could be due to inadequate diuresis, overdiuresis with subsequent volume replacement and diuretic resistance. Aggressive diuresis carries a significant risk of electrolyte and volume depletion with subsequent arrythmias, hypotension, and worsening renal function. Actually there were scant data available from randomized clinical trials to guide therapeutic choice with diuretics. Thus, the choice and dosing of diuretic therapy must be individualized based on general knowledge of potency and pharmacokinetic and pharmacodynamic considerations.

Comparative assessment of topical steroids, topical tretenoin (0.05%) and dithranol paste in alopecia areata

BACKGROUND

There have been various controversial reports regarding the efficacy of topical agents in topical therapy of alopecia areata.

AIM

The study aims to find out the effective ones among the readily available ones for a dermatologist.

MATERIALS AND METHODS

Eighty patients were chosen from the skin OPD of Bankura Sammilani Medical College, Bankura, West Bengal, after evaluating the exclusion criterions. Treatments were continued for 3 month period and a follow up after further 3 months. After dividing them into four groups-group-I (topical steroids), group-II (topical tretinoin 0.05%) group-III (dithranol paste 0.25%), and group-IV (white soft petrolatum jelly)-patients were evaluated.

RESULTS

Seventy percent of group-I, 55% of group-II, 35% of group-III, and 20% of the control group (white soft petrolatum jelly) responded favorably. Side effects in the form of dermatitis and hyperpigmentation were seen in group-III. However, no patient discontinued from the study.

CONCLUSION

We conclude that both topical steroids and tretinoin were fairly effective in limited variant of alopecia areata.

[Diagnosis and medical treatment of pulmonary arterial hypertension]

The idiopathic pulmonal arterial hypertension is characterized by a chronic proliferative conversion of the pulmonary arterial vessels leading to an increase of pulmonary vascular resistance and thus resulting in right heart failure and increase mortality rate. With growing advances in understanding of the underlying pathophysiological mechanisms and the development of modern medical treatment strategies, there is a significant improvement of the overall survival rate and quality-of life. In this review we will give an overview about the current knowledge of etiology, diagnosis and management of idiopathic pulmonal arterial hypertension.

[Perioperative antiplatelet therapy of patients with coronary stents]

The most feared complication after coronary stent implantation is the acutely occurring stent thrombosis, which usually leads to a myocardial infarction with its relatively high mortality. Dual antiplatelet therapy with acetylsalicylic acid and clopidogrel is currently the standard therapy after coronary stent implantation to prevent a life-threatening stent thrombosis. Surgery appears to increase the risk of stent thrombosis, myocardial infarction, and death, particularly when patients undergo surgery early after stent implantation. The incidence of complications is further increased when dual-antiplatelet therapy is discontinued preoperatively. This article reviews the current data of perioperative problems in patients after percutaneous coronary intervention.

[Percutaneous aortic valve replacement in high risk patients]

The degenerative, calcified aortic stenosis is the most common form of adult valvular heart disease. Surgical aortic valve replacement is the method of choice and can be performed at low risk in suitable candidates. However, a fair amount of patients is rejected from surgery due to old age and preexisting comorbidities increasing operative mortality. For this reason frequently operation is not accomplished. Today, with the development of percutaneous aortic valve replacement, the treatment of aortic stenosis has entered a new era providing a new durable treatment option.

Recent advancements for the evaluation of anti-viral activities of natural products

Significant progress has been achieved for the development of novel anti-viral drugs in the recent years. Large numbers of these newly developed drugs belong to three groups of compounds, nucleoside analogues, thymidine kinase-dependent nucleotide analogues and specific viral enzyme inhibitors. It has been found that the natural products, like plant extract, plant-derived compounds (phytochemicals) and so on, as well as traditional medicines, like Ayurvedic, traditional Chinese medicine (TCM), Chakma medicines and so on, are the potential sources for potential and novel anti-viral drugs based on different in vitro and in vivo approaches. In this chapter some of these important approaches utilised in the drug discovery process of potential candidate(s) for anti-viral agents are being discussed. The key conclusion is that natural products are one of the most important sources of novel anti-viral agents.

[Regenerative therapy in cardiology]

The aim of regenerative medicine is the reconstitution of the physiological structure of critically damaged organs. Bone marrow derived stem cells (BMDCs) show promising therapeutic potential. BMDCs are already used in oncology and are ideally suited for regenerative medicine due to their regenerative potential and safety profile. A variety of cells have been contemplated in cardiology, and there is emerging preclinical and clinical data on the feasibility and safety of different cell lines in the setting of acute myocardial infarction and chronic heart failure. In this review, the various concepts and cells will be discussed in further detail.