Raised serum homocysteine levels in patients of coronary artery disease and the effect of vitamin B12 and folate on its concentration

Homocysteine(Hcy) has been implicated as a novel risk factor of Coronary Artery Disease (CAD) among Asian Indians, but many studies done in India failed to reveal any direct correlation. It has also been reported that Folic acid and Vitamin B12 levels inversely affect serum levels of homocysteine. In this study, we looked at the levels of homocysteine among patients with CAD. The effect of Vitamin B12, Folate and other risk factors on homocysteine levels were also evaluated. Mean homocysteine levels in cases (22.81±13.9, n=70) were significantly higher (p=<0.001) than the controls (7.77±7.3, n=70). However no statistically significant correlation could be deduced between homocysteine Vitamin B12, and Folate. Cumulative analysis have indicated an increase in homocysteine levels among patients with CAD with every additional risk factor.     

LP(a) phenotypes and levels in angiographically proven coronary heart disease patients and controls

Lipoprotein Lp(a) excess has been identified as a powerful predictor of premature atherosclerotic vascular diseases. To evaluate this in a North-Indian population, 130 CAD patients and 130 controls were analyzed. The size of the apo(a) phenotypic isoforms was inversely proportional to Lp(a) concentrations. The mean concentration of Lp(a) in the CAD patients was 42±34 mg/dl whereas in the normal subjects it was much lower, 27±27 mg/dl. 157 subjects out of the total 260 subjects showed plasma levels of >20mg/dl. The frequency of high Lp(a) levels was much higher in patients(73%) than controls (43%). These data suggest (1) that there is heterogeneity of the Lp(a) polymorphism, (2) Higher Lp(a) levels were found in patients than in the controls, (3) Patients showed 1.5 fold increase in Lp(a) levels as compared to the controls. We conclude that low molecular weight apo(a) isoforms are significantly associated with increased risk of CAD in the North-Indian population.     

Serum lipid profile in patients with acute myocardial infarction

Serum lipids and lipoproteins were estimated in 29 patients with acute myocardial infarction during acute phase (day 1,2,3), predischarge and after three months. Serum total lipids, total cholesterol (TC) and LDL-cholesterol (LDLc) showed no significant change during the hospital stay and three months followup. HDL-cholesterol (HDLc), however, started falling from day 2 onwards with statistically significant reduction at pre-discharge and remained so at 3 months. The ratios of TC/HDLc and LDLc/HDLc showed significant increase on predischarge day as compared to day 1. Serum triglycerides also showed an increasing trend after myocardial infarction with a significant increase on day 3 and predischarge as compared to day 1. it is concluded that the optimum time for assessment of serum lipid profile in patients with myocardial infarction seems to be within 24 hours of the acute episode.     

Serum dehydroepiandrosterone and lipid peroxides in human volunteers of different age groups

The objective of the present study was to evaluate the changes in serum dehydroepiandrosterone (DHEA) and lipid peroxide levels during ageing in human subjects. Random blood samples were collected from a total of 128 apparently normal human volunteers of both sexes, whose age ranged between 21–70 years. The subjects were divided into groups of a decade years of age difference. Serum levels of dehydroepiandrosterone (DHEA), lipid peroxides as malondialdehyde (MDA), and insulin were analysed in all the subjects recruited in the study. In the present study there was decrease in serum DHEA levels with age (11.30 to 7.99 ng/ml). However the differences were significant only after 50 years up to 70 years. Serum MDA levels of these subjects were higher (3.91 to 4.74 ng/ml) as compared to the values reported earlier (2.64 to 3.94 ng/ml). The serum MDA levels also showed an increasing trend with age but the increase was significant only in the 40–50 years age group and values plateaud off at later ages. The MDA and DHEA levels in women in general were lower than in men and this could be due to female hormones, which are known to protect lipid against peroxidation. There was a significant negative correlation between age and DHEA (r=−0.311 P<0.05) and positive correction between MDA and age (r=+0.405 P<0.01). No significant differences were seen in serum insulin, albumin and total protein levels. These preliminary findings support the possible utility of DHEA and MDA as markers for chronological ageing.     

Effect of vitamin E on platelet enzymatic anti-oxidants in the patients of myocardial infarction

Effect of administration of 600 mg. vitamin E each day, for six days, was observed on activity of some of the anti-oxidant enzymes and levels of malondialdehyde (as an index of free radical mediated damage) in the platelets of patients reperfused after myocardial infarction. It has been found that vitamin E administration significantly lowers the level of malondialdehyde in the patients. Vitamin E administration increases the activities of anti oxidant enzymes (viz. superoxide dismutase, glutathione reductase and catalase) tested both in the patients and healthy controls. Vitamin E administration causes general stimulation of anti-oxidant enzyme activities both in healthy persons and the patients, however, lowering of lipid per-oxidation upon administration of vitamin E is specific for patients. These findings exhibit beneficial role of vitamin E administration in the management of the patients reperfused after myocardial infarction.     

Diagnosis of acute myocardial infarction: CK-MB versus cTn-T in Indian patients

The comparative diagnostic efficacy of two cardiac markers: CK-MB and cTn-T, has scarcely been investigated in Indian patients of acute myocardial infarction. The present study was conducted for the same objective. The present study comprised of 59 patients. Males were 44 (75%) and females were 15 (25 %). The age of patients ranged from 32–84 years with mean age of 62.8 yrs. The mean age of males and females were 60 and 63 yrs respectively. All patients presented with history of chest pain with a 12 leads ECG proven MI (ST Elevation, discordant T-waves). CK-MB was estimated in peripheral blood samples at 0,24,48 and 72 hours by an autoanalyzer. Following 12 hours of admission bed side Troponin-T test was done employing cTn-T marker kit. Initially (0 hr), in 50% patients CK-MB was elevated. By end of 24 hours all the patients were CKMB positive and peak level was attained at 24 hrs. Then it tended to decline over next 48 hrs. There were no false positive or negative results. The cTn-T test was positive only in 22 % of ECG positive infarctions. However, the cTn-T positive cases were always accompanied by a higher CK-MB levels. A significantly lower cTn-T positive cases in Indian patients can only be attributed to some difference in amino acid sequence of Indian cTn-T and occidental cTn-T. A larger study from other Indian cardiac centers can either substantiate or contradict our results.     

Effect of vitamin E on the platelet xanthine oxidase and lipid peroxidation in the patients of myocardial infarction

Platelets play important role in precipitating ischaemic myocardial syndromes in many ways. One of the consequences of ischaemic diseases is excessive generation of oxygen derived free radicals that have numerous pathophysiological consequences. Platelet pro-oxidant enzyme, xanthine oxidase is one of the sources of generation of free radicals. In the present paper, we report the effect of administration of vitamin E along with aspirin on the levels of platelet xanthine oxidase and extent of free radical mediated damage in the patients reperfused after myocardial infarction. Our findings show that administration of 400 mg. vitamin E for six days along with 80 mg. aspirin has an excellent anti-oxidant effect as evidenced by reduced platelet xanthine oxidase activity and lowering of malondialdehdye (MDA) levels which is an index of the extent of free radical mediated damage.     

Serum lipids during pregnancy in relation to the risk of coronary heart disease

The serum lipid classes in 75 pregnant women (25 in each trimester) and 25 matched controls were investigated. The lipid classes studied were very low density lipoproteins (VLDLc), low density lipoproteins (LDLc), high density lipoproteins (HDLc), total triacylglycerols (Tg), phospholipids (PL) and total cholesterol (Tc). It was found that there is increase in HDLc during first trimester followed by decrease during second and third trimesters. All other lipid classed including Tc and PL showed a progressive increase. Analysis of data showed that Tc/HDLc ratio has an increasing trend with parity. LDLc/HDLc also showed similar correlation. The results of our study indicates that there is likely to be increased risk for CHD in multiparous women as predicted from serum lipid parameters.     

Glycogen phosphorylase isoenzyme BB in the diagnosis of acute myocardial infarction: a meta-analysis

Background

Early diagnosis is crucial for management of patients with suspected acute myocardial infarction (AMI). Among innovative and promising biomarkers, the recent interest raised on glycogen phosphorylase isoenzyme BB (GPBB) has prompted us to perform a meta-analysis of published studies.

Materials and methods:

A systematic electronic search was carried out on PubMed, Web of Science and Google Scholar, with no date restriction, to retrieve all articles that have investigated the early diagnostic performance of GPBB in patients with suspected AMI, and directly reported or allowed calculation of sensitivity and specificity. A meta-analysis of the reported sensitivity and specificity of each study and pooled area under the curve (AUC) was then performed by random effect approach. Heterogeneity was assessed by I-square statistics.

Results:

Eight studies were finally selected for analysis (941 subjects; 506 cases and 435 controls), with a high heterogeneity (I-squared, 86.3%). The resulting pooled estimates and 95% confidence interval were 0.854 (0.801–0.891) for sensitivity, 0.767 (0.713–0.815) for specificity, 0.826 (0.774–0.870) for negative predictive value, 0.802 (0.754–0.844) for positive predictive value, and 0.754 (0.602–0.907) for AUC. In those studies that have simultaneously assessed GPBB and a troponin immunoassay, the combination of these biomarkers did not significantly improve the performance of troponin alone.

Conclusion:

GPBB does not meet the current requirements for an efficient diagnosis of AMI when used as a stand-alone test, whereas its combination with troponin merits further investigation in larger trials.     

Comparative study of serum myoglobin and creatine kinase MB isoenzyme in the detection of acute myocardial infarction

Serum creatine kinase MB isoenzyme (CKMB) and myoglobin have been studied in 35 cases with myocardial infarction. Increased values for both serum CKMB and myoglobin have been found in all the patients in the second sample collected 4 hr. after admission while in 22 patients in the first sample collected immediately after admission. Thus, the present study shows a good correlation between serum CKMB and myoglobin and therefore, suggests the possibility of using the serum myoglobin estimation in early detection of myocardial infarction either alone or in combination with the serum CKMB.     

Evaluation of clinical utility of serum enzymes and troponin—T in the early stages of acute myocardial infarction

Laboratory infarction diagnostics are based on the detection of elevated serum activities of total Creatine Kinase (CK), Creatine Kinase isoensyme MB, (CKMB), Lactate dehydrogenase (LDH), isoenzyme forms of LDH and transaminases. Determination of these cardiac marker enzymes permits a highly sensitive diagnosis of transmural myocardial infarction. In such patients the diagnosis of acute myocardial infarction can be confirmed by the clinical, symptoms, and changes in the ECG in addition to the enzyme assays. The 50 AMI patients selected in the present study were those admitted to the ICCU of Shri Krishna Hospital, Karamsad. The blood samples were taken at the time of admission (ie. within four hours of the start of chest pain). The samples were analyzed for CK, CKMB, SGOT, (Serum glutamate oxaloactate transaminase) αHBDH α-hydroxybutyrate dehydrogenase and troponin T. The serum CKMB activity in AMI showed an increase only 5–6 hours after the commencement of chest pain. The elevation in SGOT and αHBDH was still delayed. At the same time we could observe that the cardiac Troponin T (cTnT) was elevated at the time of admission of the patient itself. This increase of cTnT in AMI patients was 20 times higher than the normal blood donors. The controls included 25 normal blood donors and 25 patients with polytraumatic injuries with no chest contusion. The study shows that cTnT estimation could serve in the early diagnosis of AMI. The increase of cardiac troponin T in AMI patients was 20 times higher than the normal blood donors in AMI patients at the time of admission. Cardiac troponin T in serum appears to be a more sensitive indicator of myocardial cell injury than CKMB activity and its detection in the circulation may be a useful prognostic indicator in patients with unstable angina as well. When the blood of normal blood donors or that of patients with polytraumatic injury was analysed the troponin T values were well within the normal range in both the above categories showing that cardiac troponin T is highly specific for heart tissue. Although CKMB and cardiac troponin T are released soon after the myocardial injury, the release of cardiac troponin T is much earlier than CKMB thereby invalidating the important role of cardiac troponin T in diagnosing AMI. Cardiac troponin T has been shown to be highly sensitive for cardiac injury and not elevated in any other trauma, heavy exercise or skeletal muscle injury. Cardiac troponin T is ordinarily undetectable in healthy individuals, and so its measurement can serve as a powerful tool in the diagnosis of AMI.     

Diagnostic accuracy of heart fatty acid binding protein (H-FABP) and glycogen phosphorylase isoenzyme BB (GPBB) in diagnosis of acute myocardial infarction in patients with acute coronary syndrome

Introduction:

This study aimed to assess whether heart fatty acid-binding protein (H-FABP) and glycogen phosphorylase isoenzyme BB (GPBB) could be used for the accurate diagnosis of acute myocardial infarction (AMI) in acute coronary syndrome (ACS) patients.

Materials and methods:

The study included 108 ACS patients admitted to a coronary unit within 3 h after chest pain onset. AMI was distinguished from unstable angina (UA) using a classical cardiac troponin I (cTnI) assay. H-FABP and GPBB were measured by ELISA on admission (0 h) and at 3, 6, 12, and 24 h after admission; their accuracy to diagnose AMI was assessed using statistical methods.

Results:

From 92 patients with ACS; 71 had AMI. H-FABP and GPBB had higher peak value after 3 h from admission than cTnI (P = 0.001). Both markers normalized at 24 h. The area under the receiver operating characteristic curves was significantly greater for both markers in AMI patients than in UA patients at all time points tested, including admission (P < 0.001). At admission, the H-FABP (37%) and GPBB (40%) sensitivities were relatively low. They increased at 3 and 6 h after admission for both markers and decreased again after 24 h. It was 40% for H-FABP and approximately 2-times lower for GPBB (P < 0.01). In AMI patients, both biomarkers had similar specificities, positive- and negative-predictive values, positive and negative likelihood ratios, and risk ratios for AIM.

Conclusion:

H-FABP and GPBB can contribute to early AMI diagnosis and can distinguish AMI from UA.     

胰岛素样生长因子1与冠心病病变程度的关系

目的为了研究冠心病发病的机制. 方法测定了16例正常人血清胰岛素样生长因子1(IGF1)水平和40例冠心病患者血清IGF1水平,且把冠心病患者血清IGF1水平与冠脉造影的血管病变支数进行了比较分析. 结果冠心病患者外周血IGF1水平显著低于正常人(分别为27.23±15.48 μg/L和48.02±33.43 μg/L,P＜0.01);且在冠脉造影血管病变支数增加时其血清IGF1水平下降变得更加明显. 结论 IGF1可能参与了冠心病的病理生理过程.     

新时期日本科技政策的转型

1995年,日本国会通过了《科学技术基本法》,标志着日本为迎接挑战而做出科技政策的转型。在新的意义上理解和加强基础研究,成为日本这一科技政策转型中带有根本意义的重要问题。本文将对新时期日本科技政策转型的必要性,以及转型后日本科技政策的基本理念及其相应的举措进行简要的分析与介绍。     

我国研究生教育专业目录的“学科门类”设置质疑

从历史、现实和趋势的纵向角度,考察了我国研究生教育专业目录的学科门类设置问题,认为从适应科学技术自身发展和社会人才培养需要的实际出发,应该学习发达国家的先进经验,逐步强化一级学科建设,淡化乃至取消学科门类的设置。     

网络时代期刊论文隐形学术不端挖掘策略

【目的】抵制学术不端,期刊编辑责无旁贷,为促进学术生态环境净化,提出基于互联网的深度挖掘隐性学术不端的编辑策略。【方法】论述网络时代学术不端行为特征和发展趋势,以中国知网AMLC5.0为例,在总结学术不端检测系统不足的基础上,提出有针对性的解决方案。【结果】结合网络时代学术不端行为的演变,提出以AMLC为主,辅助多种检测手段,对存疑论文进行基于网络和论文本身信息的学术不端深度挖掘;根据期刊编辑出版特点增加检测次数;构建“以人为本”“人机合一”的学术不端鉴别体系。【结论】可在学术不端末端出口处筑起一道拦截网,对期刊抵制学术不端具有一定作用。     

中国科学院中青年杰出科技人才的年龄特征

通过对227名中国科学院50岁以下杰出科技人才的统计分析,研究其成长过程中表现出的年龄特征,上世纪90年代后我国自己培养的博士已成为杰出科技人才的主体部分。这一年龄特征与国际科技人才成长的一般规律一致,但是,在完成博士研究工作并进入职业科研活动方面,稍晚于诺贝尔科学奖获得者。     

流行性出血热血清甘油三酯改变及临床意义

分析142例流行性出血热(EHF)患者血清甘油三酯(TG)值改变,发现EHF患者各期TG均值(mmol/L)均较对照组(0.98±0.48)增高,分别为:发热期1.68±0.46,低血压期1.723±0.44,少尿期2.31±1.1,多尿期2.06±0.81,恢复期1.36±0.8.且各型TG均值(mmol/L)又有明显差别;轻型1.49±0.43,中型2.79±1.14,危重型3.48±1.20,轻中型与重危型比较P<0.05.并系统观察32例,各期增高的例数分别为:发热期64％,低血压期78％,少尿期100％,多尿期100％,恢复期为45％.故提示TG值增高与疾病的严重程度成正相关,动态观察TG值可作为判断病情轻重,观察病期及估计预后的一种参考方法.作者同时探讨了EHF患者TG值改变的机制.     

Mapping the mix: Linking instruments,settings and target groups in the study of policy mixes

This article proposes the extension of a conceptual framework aimed at analysing policy mixes and their outcomes and demonstrates its value added for the study of sustainability transitions. The argument is that policy mixes research should not focus only on the form of policy instruments, but also on their implementation context. Policy mix form designates the specific policy instruments that are involved according to a policy strategy. Policy mix context includes the specific setting where each policy measure is implemented, such as enterprise or family. It also includes the specific target group of each measure, such as youth or smokers. We apply this conceptual framework to the policy concept and implementation of tobacco control policies in Switzerland, which are an exemplary case for analysing transitions as they are geared towards behavioural change. In a mixed method approach, we triangulate different sets of quantitative and qualitative indicators in order to assess the implementation of eleven subnational policy mixes. Our findings show that taking into account the moderating role of settings between policy instruments and target groups allows for a more in depth analysis of policy processes. Observing the interactions between the four elements policy instruments, policy strategy, the implementation settings and the target groups allows capturing the complexity of policy mixes, at the crossroads of policy design, policy implementation and policy outcomes. Taking implementation settings and target groups into account in the analysis of policy mixes allows for a refined understanding of policy compliance and thus, from a broader perspective, of sustainability transitions.     

冀北小张家口超基性岩体的锆石U-Pb年龄和Hf同位素组成

采用离子探针（SHRIMP Ⅱ）测得小张家口基性-超基性岩体中的锆石主要有220±5Ma和491±7Ma两组年龄,以及一个很老的继承锆石年龄2453Ma.年龄为220±5Ma的一组锆石（A组）具有典型的岩浆型振荡环带,这组年龄应代表该岩体的侵位年龄.A组锆石的^176Hf/^177Hf比值从0.282557到0.282690,εHf（220Ma）=-2.9～＋1.66.年龄为491±7Ma的一组锆石（B组）具有变质成因的蝴蝶结构（Butterfly structure）和熔蚀边,属于继承锆石.B组锆石的^176Hf/^177Hf比值从0.282239到0.282483,εHf（491Ma）=-8.6～0.06.207Pb/206Pb年龄为2453Ma的锆石应该是岩浆侵位时从华北克拉通古元古代基底中捕获的锆石.A组锆石的Hf同位素数据表明,220Ma左右由于华北北缘岩石圈伸展,导致软流圈地幔上涌,亏损的软流圈地幔流/熔体与富集的岩石圈地幔相互作用并混合,这种混合地幔源区发生部分熔融而形成小张家口基性-超基性岩体.B组锆石可能是小张家口岩体在岩浆侵位过程中捕获的来源于富集地幔或大陆下地壳的锆石.