通心络对同型半胱氨酸诱导大鼠心肌微血管内皮细胞损伤的干预作用及氧化应激机制研究

目的:探讨通心络对同型半胱氨酸诱导大鼠心肌微血管内皮细胞损伤的干预作用及氧化应激机制。方法:采用植块法原代培养大鼠心肌微血管内皮细胞,倒置显微镜观察细胞形态并通过CD31免疫荧光法对培养的大鼠心肌微血管内皮细胞进行辨别、鉴定。用同型半胱氨酸(Hcy)建立细胞损伤模型,实验分为对照组、同型半胱氨酸组、通心络低浓度组、通心络中浓度组、通心络高浓度组。分别检测各组细胞的存活率、细胞上清液中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量、细胞内活性氧(ROS)水平、内皮素-1(ET-1)和内皮型一氧化氮合酶(e NOS)表达水平的变化。结果:与对照组相比,同型半胱氨酸组细胞存活率降低[(74.61±2.88)%vs(100.00±2.07)%],细胞上清液中MDA含量升高[(4.10±0.18)nmol/ml vs(1.92±0.10)nmol/ml],SOD活性降低[(7.55±0.71)U/ml vs(20.77±0.68)U/ml],细胞内ROS水平升高[(38.17±10.28)%vs(19.83±2.97)%],ET-1 m RNA表达上调,e NOS蛋白表达下调;与同型半胱氨酸组相比,通心络各剂量组均能不同程度的改善上述指标变化。结论:通心络能够改善同型半胱氨酸诱导的大鼠心肌微血管内皮细胞的功能损伤,并通过减轻氧化应激损伤发挥细胞保护作用。     

4,5,7-三羟异黄酮减轻高同型半胱氨酸血症导致的血管内皮损伤

目的观察植物雌激素4,5,7-三羟异黄酮(GST)对同型半胱氨酸(Hcy)诱导的血管内皮损伤的保护作用。方法健康成年雌性Wistar大鼠随机分成4组:对照组;2.5%蛋氨酸饮食组;卵巢去势+2.5%蛋氨酸饮食组;卵巢去势+2.5%蛋氨酸饮食+GST治疗组,每组8只。给予大鼠高蛋氨酸(2.5%)饮食来复制高同型半胱氨酸血症(HHcy)模型,卵巢去势+2.5%蛋氨酸饮食组和卵巢去势+2.5%蛋氨酸饮食+GST治疗组大鼠施行卵巢去势手术,GST以2.5 mg/(kg.d)剂量灌胃给药。治疗12周以后,颈总动脉采血,检测血浆中雌二醇和Hcy的水平。分离大鼠胸主动脉环,检测血管环对苯肾上腺素(PE),乙酰胆碱(Ach)和硝普钠(SNP)的反应性以评价血管功能;HE染色观察胸主动脉壁形态学的改变。体外培养内皮细胞株Eahy926,观察GST体外干预对Hcy诱导内皮细胞损伤的作用。结果高蛋氨酸饮食能够导致大鼠血浆Hcy水平显著升高,出现明显血管内皮功能和形态损伤,卵巢去势进一步加重了血浆Hcy水平的升高和血管内皮损伤。GST治疗12周能够明显减轻去卵巢HHcy大鼠的血管内皮的功能和形态损伤,而且能够降低血浆中Hcy水平;G...     

参芍胶囊对心肌缺血再灌注损伤大鼠心脏过氧化损伤的影响

目的观察参芍胶囊预处理对心肌缺血再灌注损伤(MIRI)大鼠心脏组织和功能及过氧化损伤、抗氧化能力的影响。方法采用左冠状动脉前降支结扎30 min,再灌注120 min制备心肌缺血再灌注损伤模型。将30只雄性Wistar大鼠随机分为5组:假手术组、模型组、参芍胶囊250 mg/kg组、参芍胶囊500 mg/kg组和阿托伐他汀组,每组6只。术前用药7 d。再灌注后生理记录仪记录血流动力学变化,生化法检测血清肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH)及心肌组织中丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)含量。结果与模型组比较,参芍胶囊高、低剂量组与阿托伐他汀组CK-MB和LDH均明显降低(P0.05或P0.01)。与参芍胶囊250 mg/kg组比较,参芍胶囊500 mg/kg组和阿托伐他汀组LDH显著降低(P0.01)。与模型组比较,参芍胶囊250 mg/kg组左心室内压最大上升速率(+dp/dt_(max))值明显升高(P0.05);参芍胶囊500 mg/kg组和阿托伐他汀组LVSP和-dp/dt_(min)值明显升高(P0.05),+dp/d_(max)值显著升高(P0.01),左心室舒张末压(LVEDP)值明显降低(P0.05)。与模型组比较,参芍胶囊高低剂量组与阿托伐他汀组心肌中丙二醛(MDA)明显降低(P0.05或P0.01),超氧化物气化酶、谷胱甘肽过氧化物酶明显升高(P0.05或P0.01)。结论参芍胶囊预处理能够抑制MIRI后大鼠心肌损伤,改善心脏血流动力学状态,抑制膜脂过氧化产物的生成及提高机体抗氧化损伤能力。     

依那普利叶酸片对冠心病患者血管内皮功能保护的作用机制

目的探讨依那普利叶酸片对冠状动脉粥样硬化性心脏病(冠心病)血管内皮功能保护的作用机制。方法Wistar大鼠给予高脂、高蛋氨酸饲料建立冠心病模型。造模成功后随机分为4组,分为模型对照组,依那普利叶酸片小剂量(5.4 mg/kg·d)、中剂量(10.8 mg/kg·d)组和高剂量(16.2 mg/kg·d)组,每组各10只,另取10只大鼠为正常对照组。治疗8周后,麻醉大鼠,取腹腔静脉血检测血清同型半胱氨酸(Hcy)。分离大鼠胸主动脉,分别测定血管内膜增生情况、血管内皮功能指标一氧化氮(NO)、一氧化氮合酶(NOS)、内皮素-1(ET-1)和非对称二甲基精氨酸(ADMA)及NOX4 mRNA和蛋白表达。结果①依那普利叶酸中剂量组大鼠血管NO和NOS较依那普利叶酸小剂量组显著增加(P<0.05),ET-1和ADMA较正常对照组显著增加(P<0.05);依那普利叶酸大剂量组大鼠血管NO和NOS较依那普利叶酸中剂量组显著增加(P<0.05),ET-1和ADMA较依那普利叶酸中剂量组显著增加(P<0.05)。②依那普利叶酸小剂量组血清Hcy较模型对照组显著减少(P<0.05),依那普利叶酸中剂量组大鼠血清Hcy和血管内膜厚度较依那普利叶酸小剂量组显著减少(P<0.05),依那普利叶酸大剂量组大鼠血清Hcy和血管内膜厚度较依那普利叶酸中剂量组显著增加(P<0.05)。③依那普利叶酸中剂量组大鼠血管NOX4 mRNA和蛋白的表达较依那普利叶酸小剂量组显著减少(P<0.05),依那普利叶酸大剂量组大鼠血管NOX4 mRNA和蛋白的表达较依那普利叶酸中剂量组显著减少(P<0.05)。结论依那普利叶酸片可显著抑制冠心病大鼠血管内膜增厚,改善血管内皮功能,该作用可能与其降低血清Hcy水平及抑制血管内皮NOX4基因介导NOX4信号通路有关。     

老年H型高血压病人CD62P与血小板参数变化的临床研究

目的探讨老年H型高血压病病人CD62P与血小板参数的变化及临床意义。方法选取120例老年高血压病人,根据血浆同型半胱氨酸(Hcy)水平分为H型高血压组(Hcy10μmol/L)60例和对照组(Hcy10μmol/L)60例。采用全血法流式细胞术及血球计数仪对各组CD62P、血小板参数进行测定。结果老年H型高血压病病人CD62P、Hcy、血小板平均体积(MPV)、血小板压积(PCT)和血小板体积分布宽度(PDM)明显高于对照组(P0.05),血小板计数(PLT)低于对照组(P0.05)。结论老年H型高血压病人血小板活化明显升高,易出现心脑血管事件,应采取措施积极干预措施。     

原花青素对I型糖尿病大鼠血管内皮功能、氧化性损伤和凋亡相关蛋白表达的影响

目的研究原花青素(procyanidins,PC)对糖尿病大鼠血管内皮细胞的作用,并在三种凋亡相关蛋白水平探讨作用机制。方法雄性SD大鼠,尾静脉注射链脲佐菌素(STZ)30 mg/kg造成1型糖尿病动物模型,随机分为糖尿病模型组,50 mg/kg原花青素治疗组和100 mg/kg原花青素治疗组,每组8只,另选8只健康雄性大鼠为正常对照组。各组大鼠灌服给药12周后,用血糖仪及专用血糖试纸现场检测各组大鼠空腹血糖;采用放射免疫分析仪检测血清内皮素1(ET-1)和前列环素(PGI2)水平;采用比色法检测血管内皮组织MDA含量和SOD活性;采用常规免疫组织化学染色方法对血管内皮细胞三种凋亡相关蛋白Caspase-3、Bax和Bcl-2的表达进行检测;用Olympus成像分析系统高倍镜(×400)下观察和采集显微图像,采用美国显微镜图像分析测量软件Image-Pro Plus 6.0采集整个视野黄染灰度值并自动转化为光密度值,计算出单个内皮细胞平均光密度值(mean-density),分析三种凋亡相关蛋白的表达情况。结果糖尿病模型组大鼠,与正常对照组比较,大鼠空腹血糖水平明显增高,血清ET-1含量增高和PGI2含量降低(P0.01),血管内皮组织MDA含量提高(P0.01),血管内皮组织SOD活性降低(P0.01),血管内皮Caspase-3和Bax蛋白表达均增强(P0.01),Bcl-2蛋白表达及Bcl-2和Bax蛋白表达比值(Bcl-2/Bax)均减弱(P0.01);50 mg/kg原花青素治疗组和100 mg/kg原花青素治疗组,与糖尿病模型组比较,大鼠空腹血糖水平不同程度减低(P0.05和P0.01),血清ET-1含量降低和PGI2含量升高(P0.01),血管内皮组织MDA含量降低(P0.01),血管内皮组织SOD活性提高(P0.05和P0.01),血管内皮Caspase-3和Bax蛋白表达均减弱(P0.01),Bcl-2蛋白表达及Bcl-2和Bax蛋白表达比值(Bcl-2/Bax)均提高(P0.01),SOD含量均高于糖尿病模型组。结论原花青素对糖尿病大鼠血管内皮分泌功能和氧化性损伤有调节保护作用,同时可抑制血管内皮Caspase-3和Bcl-2蛋白表达水平,促进Bcl-2表达,提高Bcl-2和Bax蛋白表达比值。     

麝香保心丸对同型半胱氨酸血症大鼠血清炎症因子IL-6和CRP的影响

目的在大鼠高同型半胱氨酸(Hcy)血症模型上,探讨麝香保心丸对血清炎症因子白介素-6(IL-6)和C反应蛋白(CRP)的影响。方法将实验动物随机分正常组、高同型半胱氨酸血症组及Hcy+麝香保心丸组,每组10只,采用酶联免疫吸附法检测血浆同型半胱氨酸浓度,采用放射免疫法检测大鼠血清IL-6和CRP含量。结果 L-蛋氨酸灌胃能够诱导大鼠高同型半胱氨酸血症模型,血清IL-6和CRP浓度有所升高(P 0.01);用麝香保心丸干预后,血清IL-6和CRP浓度有所下降(P 0.01)。结论麝香保心丸可抑制高同型半胱氨酸血症引起的炎症因子表达。     

卡托普利对同型半胱氨酸硫内酯损伤血管内皮功能的保护作用

目的探讨卡托普利对同型半胱氨酸硫内酯所致在体大鼠血管内皮功能损伤的保护作用及其机制。方法采用同型半胱氨酸硫内酯(50mg/kg)灌胃8周的方法造成大鼠的血管内皮损伤模型,治疗组同时给予卡托普利(10、20、40mg/kg)进行灌胃。检测血管内皮依赖性舒张反应、血中对氧磷酶1、血管紧张素转化酶活性,血管组织内皮细胞核因子κB活性;肝组织中对氧磷酶1mRNA表达水平。结果同型半胱氨酸硫内酯显著抑制大鼠胸主动脉的内皮依赖性舒张反应,导致大鼠血清对氧磷酶1活性的降低,肝组织对氧磷酶1mRNA表达下调;同型半胱氨酸硫内酯同时激活血管内皮细胞核因子κB活性;卡托普利呈剂量依赖性地改善同型半胱氨酸硫内酯损伤的大鼠胸主动脉的内皮依赖性舒张反应,抑制血管内皮细胞核因子κB活性;同时降低血清中血管紧张素转化酶活性、维持对氧磷酶1活性、促进对氧磷酶1mRNA的表达。结论卡托普利对同型半胱氨酸硫内酯所致大鼠血管内皮功能损伤具有保护作用。     

高同型半胱氨酸血症致动脉粥样硬化的实验研究

目的通过大鼠灌胃给予蛋氨酸复制高同型半胱氨酸血症(HHcy)动物模型,观察HHcy大鼠动脉粥样硬化(AS)的病理改变及与氧化应激的关系。方法Wistar雄性大鼠,体重120~150g,实验组每天灌胃给予蛋氨酸0.75g/kg,2次/d;叶酸、维生素B12(VB12)干预组每天灌胃给予蛋氨酸0.75g/kg,2次/d 叶酸2.5mg/kg VB1210μg/kg;对照组每天给予等容积生理盐水,连续给药10w,处死动物取血及胸主动脉。在平左心耳下缘水平取胸主动脉冰冻切片,HE染色,光镜下(×100)照相,测量动脉平滑肌相对厚度(mm),除以体重计算出每100g体重动脉平滑肌厚度指数(SMTI)。检测血浆同型半胱氨酸(Hcy)、丙二醛(MDA)和谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)活性,组间比较t检验。结果实验组大鼠灌胃给予蛋氨酸可诱发HHcy(与对照组比较P<0.01),血浆MDA含量生高(与对照组比较,P<0.01),GSH-Px、SOD活性降低(与对照组比较,P<0.01),SMTI(与对照组比较,P<0.01)。叶酸、VB12干预可降低SMTI(与实验组比较,P<0.01),血浆Hcy浓度下降(与实验组比较,P<0.01),MDA降低(与实验组比较,P<0.01),GSH-Px、SOD活性升高(与实验组比较,P<0.01)。结论高蛋氨酸可诱发HHcy,通过导致动脉平滑肌增生及过氧化状态致AS。叶酸、VB12对HHcy诱发的AS具有拮抗作用,并改善其引起的高过氧化状态。     

银杏酮酯滴丸联合阿托伐他汀对高血压伴颈动脉硬化患者血管内皮功能、血清网膜素-1和Hcy的影响

目的:观察银杏酮酯滴丸联合阿托伐他汀对高血压伴动脉硬化患者血管内皮功能、血清网膜素-1和同型半胱氨酸(Hcy)的影响。方法:选择我院收治的高血压伴颈动脉硬化患者120例为研究对象,随机分为阿托伐他汀组和联合治疗组(阿托伐他汀联合银杏酮酯滴丸治疗),各60例,两组均在健康教育、饮食、运动等干预基础上给予不同药物。治疗12周后,比较两组治疗前后血压,血脂、颈动脉内膜中层厚度(IMT)、斑块面积、内皮素-1(ET-1)、一氧化氮(NO)、血清网膜素-1、Hcy水平。结果:与治疗前比较,治疗后两组血压、血脂(除HDL-C显著升高外)、血清ET-1、Hcy水平均显著降低,IMT、斑块面积显著减小,血清NO、网膜素-1水平显著升高(P均0.01);且与阿托伐他汀组比较,联合治疗组血压、血脂(除HDL-C显著升高外)、血清ET-1[(136.42±15.57)μg/ml比(116.57±13.28)μg/ml]、Hcy[(15.46±3.25)μmol/L比(10.58±3.11)μmol/L]水平均显著降低,IMT[(1.43±0.21)mm比(1.26±0.19)mm]、斑块面积[(22.53±1.28) mm~2比(20.67±1.14) mm~2]显著减小,血清NO[(102.43±12.37)μmol/L比(129.84±13.36)μmol/L]、网膜素-1[(176.57±45.20)μg/ml比(198.73±45.38)μg/ml]水平显著升高(P0.05或0.01)。结论:高血压伴颈动脉硬化患者采用银杏酮酯滴丸并阿托伐他汀治疗,可显著降压、降血脂,改善血管内皮功能及动脉硬化程度。     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.