CYP2C19基因多态性对长期服用氯吡格雷脑梗死患者卒中复发的影响

目的探讨长期服用氯吡格雷的初发脑梗死患者卒中复发与CYP2C19基因多态性的关系。方法对78例初发脑梗死后长期(≥1 y)服用氯吡格雷的患者,根据入组时是否脑梗死复发分为复发组与未复发组,通过CYP2C19基因芯片检测系统对两组患者的CYP2C19基因型进行检测。结果 78例中,复发组32例,未复发组46例。两组患者在性别、年龄、吸烟、高血压、糖尿病、血脂等的差异均无统计学意义(均P>0.05);所检的78例共检出三种等位基因:CYP2C19*1、CYP2C19*2、CYP2C19*3,等位基因频率分别是61.54%、33.33%、5.13%。两组患者共检出6种基因型:CYP2C19*1/*1、CYP2C19*1/*2、CYP2C19*1/*3、CYP2C19*2/*2、CYP2C19*2/*3和CYP2C19*3/*3。未复发组CYP2C19*1等位基因和CYP2C19*1/*1基因型频率显著高于复发组,分别为76.1%:40.6%(P<0.01),58.7%:18.8%(P<0.001),而未复发组CYP2C19*2等位基因频率和CYP2C19*2/*2基因型频率显著低于复发组,分别为19.6%:53.1%(P<0.01),4.3%:31.3%(P<0.01),而两组其余等位基因频率和基因型频率差异无统计学意义(均P>0.05)。结论长期服用氯吡格雷的脑梗死患者卒中复发与CYP2C19基因突变有关,对于需长期服用氯吡格雷预防脑梗死复发的患者,进行CYP2C19基因型的检测是必要的。     

对氧磷酶1Q192R和L55M基因多态性与缺血性卒中再发的相关性研究

目的 分析对氧磷酶1 (paraoxonase 1,PON1)基因多态性与服用氯吡格雷后卒中再发之间的相关性.方法 从南京卒中注册系统中提取2008年5月至2010年4月首发缺血性卒中并长期服用氯吡格雷的患者.采用改良的多重高温连接酶检测反应技术对入选病例的PON1Q192R、PON1 L55M的单核苷酸基因多态性位点进行基因分型并随访,随访的主要终点事件包括缺血性脑血管事件、心肌梗死、血管性死亡;次要终点事件包括出血性血管事件.采用卡普兰-迈耶生存分析法探讨不同基因型患者终点事件的差异性.用单因素、多因素COX回归模型分析临床终点事件发生的相关危险因素.结果 共入组患者625例,平均随访期时间为(12.7±5.1)个月,其主要终点事件的发生率为13.6％ (85/625),其中再发卒中65例(10.4％),血管性死亡13例(2.1％),心肌梗死7例(1.1％).出血性事件发生13例(2.1％).PON1Q192R和PON 1L55M的最小等位基因频率分别为38.1％(238/625)和2.8％(17.5/625).携带QQ/QR的患者主要临床终点事件发生62例(15.7％),非携带者(RR)的主要终点事件发生23例(10.0％),组间差异有统计学意义(HR=1.68,95％ CI1.04～2.71,P=0.030).多因素COX回归模型纳入年龄、性别、体重指数、高血压、糖尿病、高脂血症、冠状动脉粥样硬化心脏病史、吸烟以及合并药物为相关危险因素,分析结果显示:PON1Q192基因型与缺血性卒中患者再发具有一定的相关性(HR =2.39,95％ CI 1.33 ～4.29,P=0.004).结论 在长期服用氯吡格雷抗血小板治疗的缺血性卒中患者中,PON1 Q192基因型携带者再发缺血性脑血管事件的风险明显增高,多因素分析提示PON1 Q192基因型与缺血性脑血管病患者再发具有一定相关性.     

急性脑梗死患者基因多态性对氯吡格雷疗效及终点事件的影响

目的探讨急性脑梗死患者基因多态性对氯吡格雷疗效及终点事件的影响。方法选取2016-06—2017-06新乡市第一人民医院神经内科收治的急性脑梗死患者418例。口服氯吡格雷5 d后抽取外周肘静脉血,血栓弹力图仪测定血小板抑制率。采用改良多重高温连接酶检测反应技术(iMLDR)对患者CYP2C19与ABCBl基因多态性进行分型。出院后进行24个月的随访,记录主要终点事件发生类别及时间。结果根据CYP2C19*2/*3快速代谢型、中间代谢型、慢代谢型的血小板抑制率之间,以及ABCBl C3435T不同基因型之间差异均有统计学意义(P0.01);而ABCBlT(-620)C不同基因型的血小板抑制率之间差异无统计学意义(P0.05)。校正可能的混杂因素后,进行多元线性回归分析显示,CYP2C19*2/*3、ABCBl C3435T是血小板抑制率的独立影响因素;同时还发现体重指数(BMI)26 kg/m~2也是血小板抑制率的独立影响因素。共382例患者完成随访研究,终点事件发生率为13.61%(52/382),其中缺血性脑卒中复发36例(9.42%),心肌梗死4例(1.05%),血管性死亡12例(3.14%)。根据是否携带CYP2C19*2/*3基因分为2组,生存分析Log-Rank检验显示差异有统计意义(P0.05);而ABCBlT(-620)C、ABCBl C3435T基因的显性与阴性患者生存曲线间差异无统计学意义(P0.05)。多因素Cox回归分析显示,CYP2C19*2/*3基因携带是临床终点时间的独立危险因素;同时年龄也是临床终点时间的独立危险因素。结论携带CYP2C19*2/*3、ABCBl C3435T等位基因的急性脑梗死患者氯吡格雷疗效降低,其中携带CYP2C19*2/*3等位基因的患者终点事件风险增高。     

急性缺血性脑卒中患者CYP2C 19基因分型与临床预后的相关性分析

目的探讨急性缺血性脑卒中患者CYP2C 19基因分型与临床预后的相关性。方法选取本院收治的156例应用氯吡格雷治疗的急性缺血性脑卒中患者作为研究对象,对患者进行CYP2C19*2和CYP2C19*3基因型检测,根据检测结果分为野生型组(GG)和突变型组(GA/AA)。对比两组的血小板抑制率、氯吡格雷疗效及临床预后情况。结果野生型组患者的平均血小板抑制率为(42. 42±2. 74)%,突变型组为(32. 41±2. 69)%,突变型组的平均血小板抑制率显著低于野生型组(P <0. 05)。突变型组的氯吡格雷抵抗发生率为26. 32%,显著高于野生型组的1. 25%(P <0. 05)。突变型组的预后不良发生率显著高于野生型组,卒中复发率及心脑血管不良事件总发生率也显著高于野生型组(P <0. 05)。与野生型组相比,突变型组患者随访期间累积无再发心脑血管不良事件的生存率明显更低(P <0. 05)。结论急性缺血性脑卒中患者的CYP2C 19基因分型与血小板抑制率、临床预后密切相关,携带CYP2C19突变型基因型的患者,血小板抑制率更低,氯吡格雷敏感性越差,预后不良风险越高。     

CYP2C19基因多态性与首发缺血性卒中氯吡格雷二级预防复发风险的关联研究

目的探讨CYP2C19基因多态性与规律服用氯吡格雷预防缺血性卒中二级复发风险之间的关系。方法入组首次缺血性卒中的326例汉族患者,采用DNA微阵列芯片法检测CYP2C19基因多态性,随访患者缺血性卒中复发情况,分析规律服用氯吡格雷的患者卒中复发与CYP2C19基因多态性的关系。结果对入组患者经过1～37个月[平均(14.44±5.07)个月]的随访,共139例规律服用氯吡格雷,其中29(20.86%)例出现卒中复发。中代谢型和慢代谢型患者的复发风险较快代谢型升高,比值比(odds ratio,OR)分别为3.05[95%可信区间(confidence interval,CI)1.11～8.43,P=0.025]和9.17([95%CI2.39～35.16,P0.001]。携带*2(G681A)A等位基因患者的卒中复发风险是携带G等位基因患者的2.63倍(P0.001)。携带*2突变杂合子和纯合子患者卒中复发风险分别是野生型的2.82倍(P=0.026)和9.69倍(P0.001)。携带有1个失功能(loss of function,LOF)等位基因者卒中复发的风险是未携带者的3.02倍,(95%CI 1.13～8.05,P=0.030),携带2个LOF等位基因者卒中复发的风险是未携带者的11.01倍(95%CI 2.67～45.24,P0.001)。多因素Logistic回归分析提示携带LOF等位基因是卒中复发的独立危险因素。结论规律服用氯吡格雷进行二级预防的首发缺血性卒中患者,中慢代谢型患者的卒中复发风险较快代谢型升高,携带CYP2C19 LOF等位基因是首发缺血性卒中患者卒中复发的独立危险因素。     

即时检测 CYP2C19基因型精准指导下高危非致残性缺血性脑血管事件的抗血小板治疗

目的探讨在即时检测CYP2C19基因型的精准指导下, 不同双重抗血小板方案治疗高危非致残性缺血性脑血管事件(HR-NICE)的有效性及安全性。方法采用单中心、前瞻性、随机、开放标签、终点盲法设计。连续收集2020年7月至2022年1月于徐州市中心医院脑卒中绿色通道及神经内科病房收治的HR-NICE患者, 对所有患者无创刮取颊黏膜行即时检测, 筛选CYP2C19功能缺失等位基因CYP2C19*2和CYP2C19*3的携带者, 携带1个功能缺失等位基因为CYP2C19中代谢, 携带2个功能缺失等位基因为CYP2C19慢代谢, 使用全自动医用PCR分析仪进行即时检测CYP2C19基因型, 将检测周转时间缩短至1 h。将CYP2C19基因型为中慢代谢的患者按照随机数字表法分为常规治疗组(氯吡格雷75 mg, 1次/d)、替格瑞洛组(替格瑞洛90 mg, 2次/d)和强化剂量组(氯吡格雷150 mg, 1次/d), 分别联合阿司匹林100 mg, 1次/d双重抗血小板治疗21 d。收集3组患者的一般基线资料、急性卒中Org10172治疗试验分型及90 d改良Rankin量表(mRS)评分、不良事...     

个体化抗血小板治疗对缺血性卒中二级预防的效果研究

目的 研究个体化抗血小板治疗在缺血性卒中二级预防的效果。 方法 选择2013年3月-2014年5月于陕西省人民医院就诊的急性缺血性卒中患者207例,随机分为 常规治疗组与个体化治疗组。常规治疗组应用阿司匹林100 mg/d抗血小板治疗。个体化治疗组应用 Essen卒中风险评分量表（Essen Stroke Risk Score,ESRS）将高危组给予氯吡格雷75 mg/d,低危组给 予阿司匹林100 mg/d抗血小板治疗。7 d后进行血栓弹力图（thromboela stogram,TEG）及CYP2C19基因型 检测,结合TEG及CYP2C19基因型结果,决定抗血小板治疗方案。随访1年,比较个体化治疗组和常规 治疗组患者终点事件发生率。 结果 CYP2C19快代谢基因型、中间代谢基因型患者应用氯吡格雷的血小板抑制率明显高于慢代谢 型,结果差异有显著性（P =0.018,P =0.015）。个体化治疗组（112例）和常规治疗组组（95例）终点事 件发生率差异无显著性（P＞0.01）。 结论 CYP2C19快代谢基因型、中间代谢基因型患者应用氯吡格雷的血小板抑制率明显高于慢代谢 型。与阿司匹林常规治疗方案相比,利用CYP2C19基因多态性与TEG检测指导下的个体化抗血小板方 案未显示降低缺血性卒中后终点事件发生率,可能需要更大规模、随访时间更长的研究。     

CYP2C19基因多态性对氯吡格雷药效的影响

氯吡格雷一种广泛应用的抗血小板聚集药物,在缺血性脑血管病二级预防中起着重要的作用。然而,在临床实践中不断发现,不同的患者对氯吡格雷的反应性差异比较大,某些患者对氯吡格雷的反应性较低或无反应,称之为氯吡格雷低反应或氯吡格雷抵抗,氯吡格雷的低反应或抵抗在缺血性脑血管病复发中起到重要的作用。参与氯吡格雷反应下降的因素有很多,包括基因的多态性(如细胞色素P450、ABCB1及P2Y12基因多态性)、药物的互相作用(质子泵抑制剂、他汀类等)、患者的依从性、Ⅱ型糖尿病、慢性肾病等,但目前机制尚未完全清楚。而CYP2C19作为细胞色素P450(CYP450)家族中一类重要的亚型,在多种药物代谢中体现出其重要性。氯吡格雷作为一种常见的抗血小板药物,其代谢也受CYP2C19基因多态性的影响,不同基因型患者对氯吡格雷的治疗反应性不同。文中就CYP2C19的几个主要基因多态性位点对氯吡格雷代谢的影响作综述。     

CYP2C19基因型与复发性脑梗死患者氯吡格雷抵抗的关系研究

目的通过CYP2C19基因检测及血小板聚集率综合评估氯吡格雷抵抗,指导复发性脑梗死患者合理用药。方法对2018年1-10月就诊于嘉兴市第二医院神经内科,诊断为复发性脑梗死的患者进行CYP2C19基因测序,分别收集氯吡格雷快代谢、中代谢、慢代谢基因型患者各30例,比较3组患者年龄、性别、BMI、吸烟、高血压、糖尿病及高脂血症等一般临床资料。3组均给予常规剂量氯吡格雷75 mg/d治疗,检测患者使用氯吡格雷前及使用7 d后的血小板聚集率。根据血小板聚集抑制率判断氯吡格雷抵抗情况,分析CYP2C19基因型与患者氯吡格雷抵抗的关系。筛选出氯吡格雷抵抗者(血小板聚集抑制率10%)分至氯吡格雷抵抗组,改用西洛他唑100 mg 2次/日,氯吡格雷半反应(10%≤血小板聚集抑制率30%)及氯吡格雷敏感(血小板聚集抑制率≥30%)者分至非氯吡格雷抵抗组,继续氯吡格雷75 mg/d治疗。3个月后再次检测血小板聚集率,比较不同药物的血小板聚集抑制情况,并观察终点事件发生情况(主要终点:再发脑梗死;次要终点:脑出血和死亡)。结果最终入组患者90例,其中男性49例(54.4%),年龄40～89岁,平均年龄68.27±10.14岁。快、中、慢代谢3组糖尿病(P=0.036)和氯吡格雷抵抗发生率(P0.001)差异均有统计学意义,其中慢代谢组合并糖尿病比率高于中代谢组(P=0.010),慢代谢组氯吡格雷抵抗发生率高于快代谢组(P0.001)及中代谢组(P=0.006)。氯吡格雷抵抗组患者22例(24.4%),非氯吡格雷抵抗组患者68例(75.6%)。Logistic回归分析提示,吸烟(OR 7.792,95%CI 1.899～31.968,P=0.004)、糖尿病(OR 4.466,95%CI 1.122～17.778,P=0.034)及CYP2C19基因慢代谢(OR 13.713,95%CI 2.352～79.959,P=0.004)是复发性脑梗死患者氯吡格雷抵抗的独立危险因素。非氯吡格雷抵抗组(49.51%±4.33%vs 63.73%±7.84%,P0.001)和氯吡格雷抵抗组(55.42%±6.63%vs 76.95%±7.42%,P0.001)患者3个月后的血小板平均聚集率较7 d时均下降,差异有统计学意义。3个月后较非氯吡格雷抵抗组,氯吡格雷抵抗组血小板聚集抑制率更高(21.53%±4.30%vs 14.23%±6.90%,P0.001)。入组患者随访3个月均无终点事件发生。结论吸烟、合并糖尿病及CYP2C19慢代谢基因型是复发性脑梗死患者氯吡格雷抵抗的独立危险因素。西洛他唑能有效抑制血小板聚集,可以作为氯吡格雷抵抗的复发性脑梗死患者的替代性用药。     

CYP2C19基因多态性与急性脑梗死患者氯吡格雷抵抗的关系

目的探讨CYP2C19基因多态性与急性脑梗死患者氯吡格雷抵抗的关系。方法检测118例急性脑梗死患者的CYP2C19基因,根据基因型分为野生型组、突变杂合型组及突变纯合型组。使用血栓弹力图测定二磷酸腺苷(ADP)诱导的血小板聚集抑制率,比较各组结果。结果根据基因分型,将患者分为野生型组45例(38.1%),突变杂合型组54例(45.8%)及突变纯合型组19例(16.1%)。与野生型组比较,突变纯合型组与突变杂合型组的血小板抑制率均显著下降(均P0.01),氯吡格雷抵抗率明显增高(P0.05~0.01)。与突变杂合型组比较,突变纯合型组的血小板抑制率显著下降(P0.01),氯吡格雷抵抗率差异无统计学意义。Logistic多元回归分析显示,携带CYP2C19突变杂合型等位基因及突变纯合型等位基因与血小板抑制率呈正相关,是氯吡格雷抵抗的独立危险因素(OR=2.13,95%CI:1.78~4.28,P=0.013;OR=4.44,95%CI:3.31~6.41,P=0.001)。结论 CYP2C19突变型等位基因是氯吡格雷低应答的独立危险因素。     

Epilepsy and anomalies of neuronal migration: MRI and clinical aspects

Neuronal migration disorders are the result of disturbed brain development. In such disorders, neurons are abnormally located. In diagnosing these conditions, magnetic resonance imaging is superior to any other imaging technique. This enables us to improve our knowledge of the clinical correlates of neuronal migration. With reference to migrational disorder, a retrospective study of all 303 patients with epileptic seizures referred for magnetic resonance imaging during a 3-year period was performed, 13 patients (aged 12-41, mean age 27) were identified. They represent 4.3% of the entire study group. Of the patients with known epilepsy, 6.7% and of the mentally retarded, 13.7% had migrational disorders. Four patients had schizencephaly as the dominant finding, one was classified as hemimegalencephaly, 2 had isolated heterotopias, and 6 had localized pachy- and/or poly-microgyria. The clinical pictures are complex. Ectopias of grey matter are recognised foci of epilepsy, but from an epileptological and a clinical viewpoint little attention has been given to these disorders. The present study shows that malmigration is not rare in epilepsy patients, especially not in the mentally retarded.     

Classification of methods in transcranial Electrical Stimulation (tES) and evolving strategy from historical approaches to contemporary innovations

Transcranial Electrical Stimulation (tES) encompasses all methods of non-invasive current application to the brain used in research and clinical practice. We present the first comprehensive and technical review, explaining the evolution of tES in both terminology and dosage over the past 100 years of research to present day. Current transcranial Pulsed Current Stimulation (tPCS) approaches such as Cranial Electrotherapy Stimulation (CES) descended from Electrosleep (ES) through Cranial Electro-stimulation Therapy (CET), Transcerebral Electrotherapy (TCET), and NeuroElectric Therapy (NET) while others like Transcutaneous Cranial Electrical Stimulation (TCES) descended from Electroanesthesia (EA) through Limoge, and Interferential Stimulation. Prior to a contemporary resurgence in interest, variations of transcranial Direct Current Stimulation were explored intermittently, including Polarizing current, Galvanic Vestibular Stimulation (GVS), and Transcranial Micropolarization. The development of these approaches alongside Electroconvulsive Therapy (ECT) and pharmacological developments are considered. Both the roots and unique features of contemporary approaches such as transcranial Alternating Current Stimulation (tACS) and transcranial Random Noise Stimulation (tRNS) are discussed. Trends and incremental developments in electrode montage and waveform spanning decades are presented leading to the present day. Commercial devices, seminal conferences, and regulatory decisions are noted. We conclude with six rules on how increasing medical and technological sophistication may now be leveraged for broader success and adoption of tES.     

Hepatic Considerations in the Use of Antiepileptic Drugs

Summary: Virtually all of the major antiepileptic drugs (AEDs) can cause hepatotoxicity, although fatal hepatic reactions are rare. The mechanisms, incidences, and risk profiles for such reactions differ from drug to drug. With carbamazepine and phenytoin, hepatotoxicity may be due to drug hypersensitivity. Although the profiles of patients at risk have not been well-defined for these two antiepileptic drugs, it would appear from reports in the literature that older adolescents and adults are at higher risk than children of developing serious or fatal hepatotoxicity. Once hepatotoxicity develops, mortality rates are 10–38% with phenytoin and 25% for carbamazepine. The risk profile for valproate fatal hepatotoxicity has been more clearly defined. Those at primary risk of fatal hepatic dysfunction are children under the age of 2 years who are receiving multiple anticonvulsants and also have significant medical problems in addition to severe epilepsy. The risk is considerably lower for patients over the age of 2 years on valproate monotherapy. In contrast to the risk profile with other AEDs, adults receiving valproate as monotherapy have the lowest risk of hepatotoxicity. Fatal hepatic dysfunction coincident with valproate may be the result of aberrant drug metabolism. Concomitant use of AEDs that induce microsomal P450 enzymes (e.g., phenytoin and phenobarbital) may enhance the production of a toxic metabolite, and hence the greater risk of hepatotoxicity with polypharmacy.     

Vascular Malformations and Epilepsy: Clinical Considerations and Basic Mechanisms

Summary: Vascular malformations (VMs) are associated with epilepsy. The natural history of the various VMs, clinical presentation, and tendency to provoke epilepsy determine treatment strategies. Investigations have probed the mechanisms of epileptogenesis associated with these lesions. Electrophysiologic changes are associated with epileptogenic cortex adjacent to VMs. Putative pathophysiologic mechanisms of epileptogenesis include neuronal cell loss, glial proliferation and abnormal glial physiology, altered neurotransmitter levels, free radical formation, and aberrant second messenger physiology.     

Neonatal Seizures: Problems in Diagnosis and Classification

Summary: The clinical identification of neonatal seizures is critical for the recognition of brain dysfunction; however, diagnosis is often difficult because of the poorly organized and varied nature of these behaviors. Current classification systems are limited in their ability to communicate motor, autonomic, and electroencephalo-graphic features of seizures precisely and to provide a basis for uniform effective diagnosis, therapy, and determination of prognosis. Recent investigations of neonates, utilizing bedside electroencephalographic/polygraphic/ video monitoring techniques, have provided the basis for improved diagnosis and classification of seizures in the newborn. These studies have demonstrated that not all clinical phenomena currently considered to be seizures require electrocortical epileptiform activity for their initiation or elaboration. In addition, the specific clinical character of the phenomena considered to be seizures, the clinical state of the infant, and the character of the EEG indicate the probable pathophysiological mechanisms involved and suggest probable etiologies, prognosis, and therapy. Similarities between animal models that demonstrate reflex physiology and neonates with motor automatisms and tonic posturing suggest that these clinical behaviors may not be epileptic in origin but, rather, primitive movements of progression and posture mediated by brainstem mechanisms. Although not all clinical behaviors currently considered to be neonatal seizures may have similar pathophysiological mechanisms, they are clinically significant because they all indicate brain dysfunction.     

Valproate Monotherapy in the Management of Generalized and Partial Seizures

Summary: For decades, therapeutic tradition has promoted the concept of polypharmacy in the management of epilepsy. In recent years, however, studies have shown that, for most patients, monotherapy can provide comparable or better seizure control than administration of multiple anticonvulsants, while diminishing the potential for adverse reactions, drug interactions, and poor compliance. Valproate is an important monotherapeutic agent that is highly effective in the control of idiopathic primary and secondarily generalized epilepsies, and partial seizures that do not generalize. Comparative studies have found that valproate is at least as effective as phenytoin and carbamazepine in the treatment of generalized and partial seizures. Given the similar efficacy, other factors such as pharmacokinetics and side effects may therefore determine anticonvulsant selection for monotherapy.     

Carbamazepine Efficacy and Utilization in Children

Summary: Carbamazepine is effective for preventing partial and generalized tonic-clonic seizures in children. Although absence epilepsies are more common in children than adults, an estimated 80% of children with epilepsy have seizure types or epilepsies that are potentially responsive to carbamazepine. The differential diagnosis of ictal staring is an especially important issue in children because absence and atypical absence seizures are more prevalent in children than adults. Age-related pharmacokinetic differences and drug interactions are major considerations in children. On average, children have higher clearance rates of carbamazepine, shorter half-lives, and higher ratios of carbamazepine-10, 11-epoxide to carbamazepine than adults. In addition, children with severe epilepsy are more likely to require multiple-drug therapy, which can lead to complex drug interactions. When carbamazepine is administered along with valproate, drug protein binding interactions can cause intermittent side effects.     

Un nouveau cadre conceptuel de travail pour la psychiatrie

In an attempt to place psychiatric thinking and the training of future psychiatrists more centrally into the context of modern biology, the author outlines the beginnings of a new intellectual framework for psychiatry that derives from current biological thinking about the relationship of mind to brain. The purpose of this framework is twofold. First, it is designed to emphasize that the professional requirements for future psychiatrists will demand a greater knowledge of the structure and functioning of the brain than is currently available in most training programs. Second, it is designed to illustrate that the unique domain which psychiatry occupies within academic medicine, the analysis of the interaction between social and biological determinants of behavior, can best be studied by also having a full understanding of the biological components of behavior.