Winter cardiovascular diseases phenomenon

Novel direct factor Xa inhibitory compounds from Tenebrio molitor with anti-platelet aggregation activity

Tenebrio molitor is an edible insect that has antimicrobial, anticancer, and antihypertensive effects. The aim of this study was to identify the unreported bioactive compounds from T. molitor larvae with inhibitory activities against factor Xa (FXa) and platelet aggregation. Isolated compounds were evaluated for their anti-FXa and anti-platelet aggregation properties by monitoring clotting time, platelet aggregation, FXa activity, and thrombus formation. A diketopiperazine (1, cyclo(_L-Pro-_L-Tyr)) and a phenylethanoid (2, N-acetyltyramine) were isolated and inhibited the catalytic activity of FXa in a mixed inhibition model and inhibited platelet aggregation induced by adenosine diphosphate (ADP) and U46619. They inhibited ADP- and U46619-induced phosphorylation of myristoylated alanine-rich C kinase substrate (MARCKS) and the expression of P-selectin and PAC-1 in platelets. They also improved the production of nitric oxide and inhibited the oversecretion of endothelin-1 compared to that of the ADP- or U46619-treated group. In an animal model of arterial and pulmonary thrombosis, the isolated compounds showed enhanced antithrombotic effects. They also elicited anticoagulant effects in mice. Compounds 1-2 inhibited ADP-, collagen-, or U46619-induced platelet aggregation and showed similar anti-thrombotic efficacy to rivaroxaban, a positive control. Therefore, 1-2 could serve as candidates and provide scaffolds for the development of new anti-FXa and anti-platelet drugs.

Evaluation of novel factor Xa inhibitors from Oxya chinensis sinuosa with anti-platelet aggregation activity

The edible grasshopper Oxya chinensis sinuosa is consumed worldwide for its various medicinal effects. The purpose of this study was to investigate potential bioactive antithrombotic and antiplatelet compounds from O. chinensis sinuosa. Five N-acetyldopamine dimers (1–5) were isolated from O. chinensis sinuosa and compounds 1 and 2 were identified as new chemicals with chiral centers at H-2 and H-3 of the benzo-1,4-dioxane structure. Compounds 1–4 were found to have both FXa and platelet aggregation inhibitory activities. These compounds inhibited the catalytic activity of FXa toward its synthetic substrate, S-2222, by noncompetitive inhibition, and inhibited platelet aggregation induced by ADP and U46619. Furthermore, compounds 1–4 showed enhanced antithrombotic effects, which were assessed using in vivo models of pulmonary embolism and arterial thrombosis. The isolated compounds also showed anticoagulant effects in mice. However, compounds 1–4 did not prolong bleeding time in mice, as shown by tail clipping. N-Acetyldopamine dimers, including two new stereoisomers 1 and 2, are novel antithrombotic compounds showing both FXa inhibition and antiplatelet aggregation activity with a low bleeding risk. Collectively, these results suggest that compounds 1–4 could serve as candidates and provide scaffolds for development of new antithrombotic drugs.

Anti-factor Xa activities of zingerone with anti-platelet aggregation activity

Zingerone (ZGR), a phenolic alkanone found in Zingiber officinale, has been reported to have various pharmacological activities such as anti-inflammatory, anti-apoptotic, and protecting myocardial infarction and irritable bowel disorder. The aim was to identify the unreported bioactive anti-factor Xa (FXa) and anti-platelet activities of ZGR. ZGR was evaluated for their anti-FXa and anti-platelet aggregation properties by monitoring clotting time, platelet aggregation, FXa activity and production, and thrombus formation. ZGR reduced activated partial thromboplastin time and it inhibited the catalytic activity of FXa toward its substrate S-2222 in a noncompetitive inhibition model and inhibited platelet aggregation induced by adenosine diphosphate (ADP) and U46619 (not thrombin). However, ZGR did not prolong bleeding time in mice, as shown by tail clipping. ZGR also inhibited ADP- and U46619- induced phosphorylation of myristolated alanine-rich C-kinase substrate (MARCKS) and the expressions of P-selectin and PAC-1 in platelets. In an animal model of arterial and pulmonary thrombosis, ZGR showed enhanced antithrombotic effects. ZGR also elicited anticoagulant effects in mice. Our results reveal that ZGR is an antithrombotic compound with both FXa inhibitory and anti-platelet aggregation activities. Collectively, these results show that ZGR could serve as candidates and provide scaffolds for the development of new anti-FXa and anti-platelet drugs.

Diabetes and impaired glucose metabolism is associated with more cold-related cardiorespiratory symptoms

AIMS

Diabetes and impaired glucose metabolism cause metabolic, neural and circulatory disturbances that may predispose to adverse cooling and related symptoms during the cold season. This study assessed the prevalence of cold-related cardiorespiratory symptoms in the general population according to glycaemic status.

METHODS

The study population consisted of 2436 men and 2708 women aged 45-74years who participated in the National FINRISK cold sub-studies in 2002 and 2007. A questionnaire assessed cold-related symptoms (respiratory, cardiac, peripheral circulation). Glycaemic status was determined based on fasting blood glucose, oral glucose tolerance tests or reported diagnosis of diabetes and categorized into normal glucose metabolism, impaired fasting blood glucose, impaired glucose tolerance, screening-detected type 2 diabetes and type 2 diabetes.

RESULTS

Type 2 diabetes was associated with increased odds for cold-related dyspnoea [Adjusted OR 1.72 (95% CI, 1.28-2.30)], chest pain [2.10 (1.32-3.34)] and respiratory symptoms [1.85 (1.44-2.38)] compared with normal glucose metabolism. Screened type 2 diabetes showed increased OR for cold-related dyspnoea [1.36 (1.04-1.77)], cough [1.41 (1.06-1.87)] and cardiac symptoms [1.51 (1.04-2.20)]. Worsening of glycaemic status was associated with increased odds for cold-related dyspnoea (from 1.16 in impaired fasting glucose to 1.72 in type 2 diabetes, P=0.000), cough (1.02-1.27, P=0.032), chest pain (1.28-2.10, P=0.006), arrhythmias (0.87-1.74, P=0.020), cardiac (1.11-1.99, P=0.000), respiratory (1.14-1.84, P=0.000) and all symptoms (1.05-1.66, P=0.003).

CONCLUSIONS

Subjects with diabetes and pre-diabetes experience more cold-related cardiorespiratory symptoms and need instructions for proper protection from cold weather to reduce adverse health effects.

Pregnancy outcome and ultraviolet radiation; A systematic review

BACKGROUND

Season and vitamin D are indirect and direct correlates of ultraviolet (UV) radiation and are associated with pregnancy outcomes. Further to producing vitamin D, UV has positive effects on cardiovascular and immune health that may support a role for UV directly benefitting pregnancy.

OBJECTIVES

To investigate the effects of UV exposure on pregnancy; specifically fetal growth, preterm birth and hypertensive complications.

METHODS

We conducted a systematic review of Medline, EMBASE, DoPHER, Global Health, ProQuest Public Health, AustHealth Informit, SCOPUS and Google Scholar to identify 537 citations, 8 of which are included in this review. This review was registered on PROSPERO and a. narrative synthesis is presented following PRISMA guidance.

RESULTS

All studies were observational and assessed at high risk of bias. Higher first trimester UV was associated with and improved fetal growth and increased hypertension in pregnancy. Interpretation is limited by study design and quality. Meta-analysis was precluded by the variety of outcomes and methods.

DISCUSSION

The low number of studies and risk of bias limit the validity of any conclusions. Environmental health methodological issues are discussed with consideration given to design and analytical improvements to further address this reproductive environmental health question.

CONCLUSIONS

The evidence for UV having benefits for pregnancy hypertension and fetal growth is limited by the methodological approaches utilized. Future epidemiological efforts should focus on improving the methods of modeling and linking widely available environmental data to reproductive health outcomes.

Seasonal variations of temperature-related mortality burden from cardiovascular disease and myocardial infarction in China

Incidence rate of cardiovascular disease (CVD) has significant seasonal trend, being higher in winter. However, the extent to which the seasonal variation of CVD deaths was caused by temperature remains unclear. We obtained daily data on temperature and CVD and myocardial infarction (MI) mortality from nine Chinese mega-cities during 2007-2013. Distributed lag non-linear models were applied to assess the city-specific temperature-related daily excess deaths across lag 0-21 days, using the minimum-mortality temperature as reference. Then, estimates of excess deaths in four seasons were separately aggregated from the daily series, and its ratio to the corresponding total deaths produced seasonal attributable fraction (AF). In total, 1,079,622 CVD and 201,897 MI deaths were recorded in the nine Chinese cities. Significant and non-linear associations between temperature and mortality were observed, with a total of 195,516 CVD and 50,658 MI deaths attributable to non-optimum temperatures. 103,439 (95% empirical CI: 54,475-141,537) CVD and 24,613 (5891-36,279) MI deaths related to non-optimum temperature occurred in winter, compared with 15,923 (1436-28,853) and 4946 (-325-9016) in summer. Temperature-related AFs were higher among MI than CVD, with AFs of 42% (9-62%) and 35% (19-48%) in winter, and 13% (-1-23%) and 8% (1-14%) in summer, respectively. This study may have important implications for developing effective targeted intervention measures on CVD events.

Seasonal and temperature modifications of the association between fine particulate air pollution and cardiovascular hospitalization in New York state

It is known that extreme temperature and ambient air pollution are each independently associated with human health outcomes. However, findings from the few studies that have examined modified effects by seasons and the interaction between air pollution and temperature on health endpoints are inconsistent. This study examines the effects of short-term PM_2.5 (particulate matter less than or equal to 2.5μm in aerodynamic diameter) on hospitalization for cardiovascular diseases (CVDs), its modifications by season and temperature, and whether these effects are heterogeneous across different regions in New York State (NYS). We used daily average temperature and PM_2.5 concentrations as exposure indicators and performed a time series analysis with a quasi-Poisson model, controlling for possible confounders, such as time-relevant variables and dew point, for CVDs in NYS, 1991-2006. Stratification parametric models were applied to evaluate the modifying effects by seasons and temperature. Across the whole year, a 10-μg/m³ increment in PM_2.5 concentration accounted for a 1.37% increase in CVDs (95% confidence interval (CI): 0.90%, 1.84%) in New York City, Long Island & Hudson. The PM_2.5 effect was strongest in winter, with an additional 2.06% (95% CI: 1.33%, 2.80%) increase in CVDs observed per 10-μg/m³ increment in PM_2.5. Temperature modified the PM_2.5 effects on CVDs, and these modifications by temperature on PM_2.5 effects on CVDs were found at low temperature days. These associations were heterogeneous across four PM_2.5 concentration regions. PM_2.5 was positively associated with CVD hospitalizations. The short-term PM_2.5 effect varied with season and temperature levels, and stronger effects were observed in winter and at low temperature days.

Cardiovascular burden and percutaneous interventions in Russian Federation: systematic epidemiological update

The situation with cardiovascular (CV) burden in Russian population is alerting, and becomes of interest due to high CV mortality, and shorter lifespan if compare with the Western society amid the absence of the established monitoring or screening system for major CV risk factors. The purpose of this systematic epidemiological update was to explore CV burden in Russia. The study represents pooled results with a systematic epidemiological review of the national mass screening, selected randomized clinical trials and statistical datasets of the national public health CV institutions exploring the trends of the CV burden in all 83 regions of Russia. We overviewed data from a number of the available Russian-speaking national data sources of 2001-2014, and NANOM-FIM trial (NCT01270139) as the only available real-world population study. The CV diseases in Russia accounted for 54.9% of all deaths in 2011-2014. The death rate was 13.3 per 1,000 citizens with CV mortality of 653.9 per 100,000. The life expectancy achieves 64.3 years for male and 76.1 years for female. The mean age of pts in trial was 51.6 years (77.2% males). A total of 175 Russian PCI centers implemented 205,902 angio a year, and 75,378 PCI achieving 531 PCI per 1,000,000 with placement of 101,451 stents (1.37 stents per PCI; 48,057 DES). The smoking (17.3% of screened with a 2,786 cigarettes a year; 70.6% in trial), excessive alcohol consumption (1.8% of screened with a 11.6 L per year; 50.6% in trial), unhealthy Russian diet (abundance of carbohydrates/sugar, saturated and trans fats in 24.3% of screened), psychosocial factors (20%) and physical inactivity (19.6% of screened) remain the major modifiable risk factors. They, in turn, affect such risk factors as dyslipidemia (86.7% in trial), obesity (16.7% of screened; BMI in trial was 28.4), and hypertension (40.8% suffered; 86.1% in trial). CV mortality was not directly associated with a level of poverty (r=0.26, P=0.02) or socio-economic development (P>0.05) in regions. The documented 27% 10-year decline of CV mortality was interpreted as a success of the national policy. Mortality statistics show the stark reality of a high CV burden in Russia. New national program and aggressive emerging efforts are required to tackle CV diseases in Russia.

Inhibition of platelet aggregation and thrombosis by indole alkaloids isolated from the edible insect Protaetia brevitarsis seulensis (Kolbe)

Protaetia brevitarsis seulensis (Kolbe) has been temporarily registered as a food material by the Ministry of Food and Drug Safety of Korea (MFDS). The current study aimed to discover small antithrombotic molecules from this edible insect. Five indole alkaloids, 5‐hydroxyindolin‐2‐one (1), (1R,3S)‐1‐methyl‐1,2,3,4‐tetrahydro‐β‐carboline‐3‐carboxylic acid (2), (1S,3S)‐1‐methyl‐1,2,3,4‐tetrahydro‐β‐carboline‐3‐carboxylic acid (3), (3S)‐1,2,3,4‐tetrahydro‐β‐carboline‐3‐carboxylic acid (4) and L‐tryptophan (5), were isolated from the insect. Among them, compounds 1 and 2 prolonged aPTT and PT and impaired thrombin and FXa generation on HUVEC surface. Moreover, these compounds inhibited platelet aggregation. Antithrombotic effects of compounds 1 and 2 were further confirmed in pre‐clinical models of pulmonary embolism and arterial thrombosis. Collectively, these results demonstrated that compounds 1 and 2 could be effective antithrombotic agents and serve as new scaffolds for the development of antithrombotic drug.

Pulmonary embolism: Does the seasonal effect depend on age? A 12-year nationwide analysis of hospitalization and mortality

BACKGROUND

Circannual variations in the incidence and mortality of pulmonary embolism (PE) have been previously described although conflicting observations have been reported. However, the association between age and seasonal variations of incidence and mortality rates is not established. This nationwide study aimed to assess the seasonal pattern in hospitalizations and mortality for PE along with the effect of age.

METHODS

Comprehensive records from the French hospital discharge databases between 2002 and 2013 and death certificates between 2000 and 2010 were used. For each outcome and separately for each sex, monthly event counts were analyzed using quasi-Poisson models with tensor-products of regression splines, including a seasonal component and controlling for the underlying time trend, age of patients and population size changes.

RESULTS

During the period studied, 599,432 patients with PE were hospitalized and 150,404 death certificates mentioned a PE. Compared with summer months, the winter peak was associated with 25% increasing rates in hospitalizations and mortality. The rates ratio of hospitalizations between the winter peak and the summer trough increased with age. The winter excess of incidence raised from 10%, IC 95% [5-16] in 30-year-old men to 33% [31-35] in 75year-old men. In the same way, the incidences at the peak time was 13% [9-18] and 34% [31-36] higher in 30 and 75-year-old women respectively.

CONCLUSION

Based on large nationwide study, our study showed a clear seasonal pattern both on PE incidence and mortality. In addition, our data supported an association of age on the PE seasonal variations.

The burden of stroke mortality attributable to cold and hot ambient temperatures: Epidemiological evidence from China

BACKGROUND

Few data are available on the attributable burden, such as absolute excess or relative excess, of stroke death due to temperature.

METHODS

We collected data on daily temperature and stroke mortality from 16 large Chinese cities during 2007-2013. First, we applied a distributed lag non-linear model to estimate the city-/age-/gender-specific temperature-mortality association over lag 0-14days. Then, pooled estimates were calculated using a multivariate meta-analysis. Attributable deaths were calculated for cold and heat, defined as temperatures below and above the minimum-mortality temperature (MMT). Moderate and extreme temperatures were defined using cut-offs at the 2.5th and 97.5th percentiles of temperature.

RESULTS

The city-specific MMT increased from the north to the south, with a median of 24.9(o)C. Overall, 14.5% (95% empirical confidence interval: 11.5-17.0%) of stroke mortality (114, 662 deaths) was attributed to non-optimum temperatures, with the majority being attributable to cold (13.1%, 9.7-15.7%). The proportion of temperature-related death had a decreasing trend by latitude, ranging from 22.7% in Guangzhou to 6.3% in Shenyang. Moderate temperatures accounted for 12.6% (9.1-15.3%) of stroke mortality, whereas extreme temperatures accounted for only 2.0% (1.6-2.2%) of stroke mortality. Estimates of death burden due to both cold and heat were higher among males and the elderly, compared with females and the youth.

CONCLUSIONS

The burden of temperature-related stroke mortality increased from the north to the south. Most of this burden was caused by cold temperatures. The stroke burden was higher among males and the elderly. This information has important implications for preventing stroke due to adverse temperatures in vulnerable subpopulations in China.

Seasonal Changes in the Incidence of Transient Global Amnesia

Background and Purpose

Transient global amnesia (TGA) is a stereotypic condition characterized by anterograde and retrograde amnesia that typically resolves within 24 hours. The pathophysiology of TGA is still unclear. We noted that patients hospitalized with TGA tend to appear in seasonal clusters, and decided to investigate this phenomenon.

Methods

Every patient with acute presentation of amnesia at our medical center is hospitalized for observation and evaluation. We reviewed the monthly occurrence of TGA in our patient population between 2000 and 2014, and compared this to non-TGA hospitalizations during the same time period.

Results

During the analysis period, 154 patients who met the criteria for TGA were hospitalized, as well as 259,007 non-TGA hospitalizations. The annual occurrence of TGA ranged from 5 to 16 hospitalizations. There were 91 TGA events in women and 63 in men, in subjects aged 62.8±10.6 years (mean±SD). The incidence was maximal during December [odds ratio (OR)=2.83, 95% confidence interval (CI)=1.20–6.67] and March (OR=2.77, 95% CI=1.17–6.56), and minimal from April to August. The incidence exhibited an increase followed by a decrease from October to February. A seasonal trend was observed as well, with incidence peaks occurring in winter (OR=1.82, 95% CI=1.12–2.96) and spring (OR=1.80, 95% CI=1.10–2.94).

Conclusions

Our findings suggest that the incidence of TGA exhibits seasonal variations. This observation may help to improve the understanding of the pathophysiology underlying TGA.

Antithrombotic and antiplatelet activities of small-molecule alkaloids from Scolopendra subspinipes mutilans

The aim of this study was to discover small-molecule anticoagulants from Scolopendra subspinipes mutilans (SSM). A new acylated polyamine (1) and a new sulfated quinoline alkaloid (2) were isolated from SSM. Treatment with the new alkaloids 1, 2, and indole acetic acid 4 prolonged the activated partial thromboplastin time and prothrombin time and inhibited the activity and production of thrombin and activated factor X. Furthermore, compounds 1, 2, and 4 inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation. In accordance with these potential in vitro antiplatelet activities, compounds 1, 2, and 4 showed enhanced antithrombotic effects in an in vivo pulmonary embolism and arterial thrombosis model. Compounds 1, 2, and 4 also elicited anticoagulant effects in mice. Collectively, this study may serve as the groundwork for commercializing SSM or compounds 1, 2, and 4 as functional food components for the prevention and treatment of pathogenic conditions and serve as new scaffolds for the development of anticoagulants.

Antithrombotic and antiplatelet activities of pelargonidin in vivo and in vitro

Pelargonidin is a well-known red pigment found in plants, and has been reported as having important biological activities that are potentially beneficial for human health. However, the possible roles of pelargonidin as an anticoagulant and the underlying mechanism have not yet been elucidated. We tested the effect of pelargonidin and its glucoside-conjugated form, pelargonidin-3-glucoside, on the clotting times, such as activated partial thromboplastin time (aPTT) and prothrombin time (PT), and the activities and productions of thrombin and activated factor X (FXa). Furthermore, the effects of pelargonidin on the fibrin polymerization, platelet aggregation, and the ratio of plasminogen activator inhibitor-1 (PAI-1) to tissue plasminogen activator were determined. Pelargonidin, but not pelargonidin-3-glucoside, prolonged the aPTT and PT, and inhibited the activity and production of thrombin and FXa in human umbilical vein endothelial cells. Furthermore, pelargonidin inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation and elicited anticoagulant effects in mice. In addition, pelargonidin significantly reduced PAI-1 to t-PA ratio. Collectively, these results indicate that the anthocyanin pelargonidin possesses antithrombotic activity, and can be beneficial in preventing thrombus formation, thus improving blood circulation.

Fabrication and effect on regulating vSMC phenotype of a biomimetic tunica media scaffold

We constructed a bFGF@TGF-β1 loaded porous film-like PLGA scaffold with dual surface topography of nanofiber and micro-orientation structures for regulating the phenotype of vascular smooth muscle cell (vSMC).

[Heat and cardiovascular diseases: A review of epidemiological surveys]

The review summarizes epidemiologic data on the effects of heat on cardiovascular morbidity and mortality. Patients with heart failure and cardiac arrhythmias are most susceptible to negative heat exposure. At the same time, measures aimed at preserving the health of the population lead to a considerable reduction in losses associated with an abnormal rise in air temperature.

Seasonal Variations of Complete Blood Count and Inflammatory Biomarkers in the US Population - Analysis of NHANES Data

Background

Recent studies reported seasonal differences in gene expression in white blood cells, adipose tissue, and inflammatory biomarkers of the immune system. There is no data on the seasonal variations of these biomarkers in the US general population of both children and adults. Then aim of this study is to explore the seasonal trends in complete blood count (CBC), and C-reactive protein (CRP) in a large non-institutionalized US population.

Methods

Seven cross-sectional data collected in the National Health and Nutrition Examination Survey (NHANES) during 1999–2012 were aggregated; participants reporting recent use of prescribed steroids, chemotherapy, immunomodulators and antibiotics were excluded. Linear regression models were used to compare levels of CBC and CRP between winter-spring (November-April) and summer-fall (May-October), adjusting for demographics, personal behavioral factors, and chronic disease conditions.

Results

A total of 27,478 children and 36,644 adults (≥18 years) were included in the study. Levels of neutrophils, white blood cell count (WBC), and CRP were higher in winter-spring than summer-fall (p≤0.05). Red blood cell components were lower in winter-spring than in summer-fall, while the opposite was seen for platelets.

Conclusions

This large population-based study found notable seasonal variations in blood cell composition and inflammatory biomarkers, with a more pro-inflammatory immune system seen in winter-spring than summer-fall. The red blood cell patterns could have implications for the observed cardio-vascular seasonality.

Spatial analysis of myocardial infarction in Iran: National report from the Iranian myocardial infarction registry

Background:

Myocardial infarction (MI) is a leading cause of mortality and morbidity in Iran. No spatial analysis of MI has been conducted to date. The present study was conducted to determine the pattern of MI incidence and to identify the associated factors in Iran by province.

Materials and Methods:

This study has two parts. One part is prospective and hospital-based, and the other part is an ecological study. In this study, the data of 20,750 new MI cases registered in Iranian Myocardial Infarction Registry in 2012 were used. For spatial analysis in global and local, spatial autocorrelation, Moran's I, Getis-Ord, and logistic regression models were used. Data were analyzed by Stata software and ArcGIS 9.3.

Results:

Based on autocorrelation coefficient, a specific pattern was observed in the distribution of MI incidence in different provinces (Moran's I: 0.75, P < 0.001). Spatial pattern of incidence was approximately the same in men and women. MI incidence was clustering in six provinces (North Khorasan, Yazd, Kerman, Semnan, Golestan, and Mazandaran). Out of the associated factors with clustered MI in six provinces, temperature, humidity, hypertension, smoking, and body mass index (BMI) could be mentioned. Hypertension, smoking, and BMI contributed to clustering with, respectively, 2.36, 1.31, and 1.31 odds ratio.

Conclusion:

Addressing the place-based pattern of incidence and clarifying their epidemiologic dimension, including spatial analysis, has not yet been implemented in Iran. Report on MI incidence rate by place and formal borders is useful and is used in the planning and prioritization in different levels of health system.

Stroke subtypes and factors associated with ischemic stroke in Kinshasa, Central Africa

BACKGROUND AND PURPOSE

Ischemic stroke causes death and disability worldwide. Better understanding and controlling factors associated will improve the prevention of the disease. This study reviews records of patients with ischemic stroke in Central Africa.

MATERIAL AND METHODS

Patients of Bantu ethnicity with clinical diagnosis of stroke and lesion on computed tomography scan from January 2011 to December 2012 were selected. Computed tomographic subtypes of ischemic stroke and factors associated were considered with tropical seasonal variation.

RESULTS

Of the 303 first-ever stroke patients (average age 53 years old, range 3- 84 years old; 62% male) were included in the study. The prevalence of computed tomography stroke subtypes was: lacunar infarct (63%) and non lacunar infarct lesion (37%). Silent brain infarct was seen in 9 % of patients. Prevalence of factors associated with ischemic stroke was: age≥60 years old (55%); male gender (63%), chronic and uncontrolled hypertension (54%) and type 2 Diabetes mellitus (11%). A seasonal high prevalence was observed in warmer season (p < 0.05).

CONCLUSIONS

This study shows a high prevalence of lacunar infarct than non lacunar in Bantu of Central Africa.

Seasonal Variation in Paroxysmal Atrial Fibrillation: A Systematic Review

INTRODUCTION

A variety of cardiovascular diseases have been demonstrated to have seasonal variations with peaks in the winter and troughs in the summer. Studies regarding atrial fibrillation (AF) have had varying results and this review describes the current data regarding the seasonal variation of AF and mechanisms mediating this seasonal fluctuation.

METHODS

A systematic review was conducted of PubMed, EBSCO and OVID for manuscripts describing the association between seasonal variation and the occurrence of AF. Studies meeting eligibility criteria were assessed for quality and reporting bias. Data was extracted in regards to the following associations: seasonal variation and AF paroxysms, temperature and AFparoxysms, duration of daylight and AF paroxysms, barometric pressure and AF paroxysms, alcohol and AF paroxysms, as well as seasonal variation and AF related stroke.

RESULTS

A total of 15 studies were identified for inclusion. Of these, 11 studies assessed seasonal variation and the remaining 4 studies assessed seasonal variation in AF related stroke. AF paroxysms peaked in winter with a trough in summer. There was an inverse correlation between temperatures as well barometric pressure and the occurrence of AF paroxysms and a positive correlation with duration of daylight.

CONCLUSIONS

The rate of occurrence of paroxysmal AF varies by seasons and is greatest during winter and least in summer.

Characteristics of sudden bath-related death investigated by medical examiners in Tokyo, Japan

Background

Sudden bath-related deaths occur frequently in Japan, particularly among elderly people. However, the precise mechanism of bath-related death remains uncertain, and effective prevention strategies have not been established.

Methods

Cases of bath-related deaths (n = 3289) were selected from all cases handled by the Tokyo Medical Examiner’s Office from 2009 to 2011 (N = 41 336). The ages and occurrence dates were examined, and major autopsy findings, including toxicological analysis, were evaluated for the autopsied cases (n = 550).

Results

Most cases occurred in individuals older than 60 years of age during winter. Analysis of autopsy findings revealed water inhalation signs in many cases (n = 435, 79.1%). Circulatory system diseases constituted more than half of the pathological findings regarding factors that may have contributed significantly to death (n = 300, 54.5%), and cardiac lesions were the most common pathological finding (n = 250, 45.5%). However, approximately one-third of the cases exhibited no remarkable pathological findings (n = 198, 36.0%). A quarter of all cases involved blood ethanol levels that exceeded 0.5 mg/mL (n = 140).

Conclusions

The results suggested that drowning plays an important role in the final process of bath-related death. Circulatory system diseases may be the primary underlying pathology; however, there were variations in the medical histories and pathologies of cases of bath-related death. From a preventive perspective, family members should pay attention to elderly people with circulatory system diseases during bathing, particularly in winter. Additionally, the notion that ill or inebriated individuals should not take baths should be reinforced.

Azelnidipine inhibits cultured rat aortic smooth muscle cell death induced by cyclic mechanical stretch

Acute aortic dissection is the most common life-threatening vascular disease, with sudden onset of severe pain and a high fatality rate. Clarifying the detailed mechanism for aortic dissection is of great significance for establishing effective pharmacotherapy for this high mortality disease. In the present study, we evaluated the influence of biomechanical stretch, which mimics an acute rise in blood pressure using an experimental apparatus of stretching loads in vitro, on rat aortic smooth muscle cell (RASMC) death. Then, we examined the effects of azelnidipine and mitogen-activated protein kinase inhibitors on mechanical stretch-induced RASMC death. The major findings of the present study are as follows: (1) cyclic mechanical stretch on RASMC caused cell death in a time-dependent manner up to 4 h; (2) cyclic mechanical stretch on RASMC induced c-Jun N-terminal kinase (JNK) and p38 activation with peaks at 10 min; (3) azelnidipine inhibited RASMC death in a concentration-dependent manner as well as inhibited JNK and p38 activation by mechanical stretch; and (4) SP600125 (a JNK inhibitor) and SB203580 (a p38 inhibitor) protected against stretch-induced RASMC death; (5) Antioxidants, diphenylene iodonium and tempol failed to inhibit stretch-induced RASMC death. On the basis of the above findings, we propose a possible mechanism where an acute rise in blood pressure increases biomechanical stress on the arterial walls, which induces RASMC death, and thus, may lead to aortic dissection. Azelnidipine may be used as a pharmacotherapeutic agent for prevention of aortic dissection independent of its blood pressure lowering effect.

Cardiac repolarization and autonomic regulation during short-term cold exposure in hypertensive men: an experimental study

OBJECTIVES

The aim of our study was to assess the effect of short-term cold exposure, typical in subarctic climate, on cardiac electrical function among untreated middle-aged hypertensive men.

METHODS

We conducted a population-based recruitment of 51 hypertensive men and a control group of 32 men without hypertension (age 55-65 years) who underwent whole-body cold exposure (15 min exposure to temperature -10°C, wind 3 m/s, winter clothes). Conduction times and amplitudes, vectorcardiography, arrhythmias, and heart rate variability (autonomic nervous function) were assessed.

RESULTS

Short-term cold exposure increased T-peak to T-end interval from 67 to 72 ms (p<0.001) and 71 to 75 ms (p<0.001) and T-wave amplitude from 0.12 to 0.14 mV (p<0.001) and from 0.17 to 0.21 mV (p<0.001), while QTc interval was shortened from 408 to 398 ms (p<0.001) and from 410 to 401 ms (p<0.001) among hypertensive men and controls, respectively. Cold exposure increased both low (from 390 to 630 ms2 (p<0.001) and 380 to 700 ms2 (p<0.001), respectively) and high frequency heart rate variability (from 90 to 190 ms2 (p<0.001) and 150 to 300 ms2 (p<0.001), respectively), while low-to-high frequency-ratio was reduced. In addition, the frequency of ventricular ectopic beats increased slightly during cold exposure. The cold induced changes were similar between untreated hypertensive men and controls.

CONCLUSIONS

Short-term cold exposure with moderate facial and mild whole body cooling resulted in prolongation of T-peak to T-end interval and higher T-wave amplitude while QTc interval was shortened. These changes of ventricular repolarization may have resulted from altered cardiac autonomic regulation and were unaffected by untreated hypertension.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02007031.

[Trends in hospitalizations of patients with acute coronary syndrome and indicators of the atmospheric state in Moscow in 2009-2012]

AIM

To identify the meteorological factors or their combinations, which are most significant for the development of acute coronary syndrome (ACS) in different seasons.

SUBJECTS AND METHODS

A Statistica package was used to make an exploration analysis of the data of the A.S. Puchkov Central Emergency Medical Care Station on 63,412 admissions of patients diagnosed with acute myocardial infarction (AMI) to Moscow hospitals in 2009-2012 and those of the Hydrometeorology Center of Russia on weather conditions in the period under study.

RESULTS

Among the 63,412 patients, there were more men than women (p < 0.000005). Two long frost periods and three long abnormal heat periods were recorded in 2009-2012. In summer, the number of patients with a prehospital diagnosis of AMI was an average 19-22% less than in the other seasons. There was no peak in the number of hospitalizations during the abnormally hot summer of 2010. Air temperature proved to be a factor that was most strongly associated with the trend in AMI hospitalizations in men (MS = 1011.52, MSor = 27.27; p < 0.00005) and women (MS = 895.36, MSor = 25.37; p < 0.00005). The number of hospitalizations was negatively associated with daily average temperature in its positive range. In summer, the interdaily temperature difference turned out to be statistically significant; the highest number of hospitalizations was noted when it grew 6 °C colder. On days off, the number of admitted patients was 25% less than that on weekdays.

CONCLUSION

The trend in hospitalizations for a referral diagnosis of AMI has a significant seasonal component. Their number was minimal in summer, including in the abnormally hot summer of 2010. Air temperature is the most important factor. Positive temperature was found to be strongly negatively correlated with diagnosed AMI hospitalizations.