低氧诱导大鼠肺静脉重塑及下调其过氧化物酶体增殖物受体γ的表达

目的 目前研究发现肺静脉参与低氧性肺动脉高压疾病的发生发展.低氧造成的肺血管收缩反应和肺血管重塑不仅发生于肺动脉,而且包括肺静脉.然而慢性低氧导致肺静脉重塑的机制仍不清楚,故本文主要观察慢性低氧对大鼠肺静脉重塑的影响,并研究其分子机制.方法 SD大鼠20只,体重200 ～ 250 g,按随机数字表法分为常氧组和慢性低氧组(CH组),每组10只,CH组放入全自动缺氧箱饲养,21 d后测量右心室收缩压(right ventricular systolic pressure,RVSP)及平均右心室压(mean right ventricular pressure,mRVP);解剖心脏计算右心室肥厚指数[RV/(LV+S)];取右肺组织做VG染色并测量小静脉血管管腔面积,计算血管中膜厚度百分比(WT％);Western blot法检测远端肺静脉平滑肌组织和原代培养的大鼠远端肺静脉平滑肌细胞(PVSMCs)中过氧化物酶体增殖物受体(PPARγ)蛋白的表达.结果 与常氧组[(27.06 ±2.10)、(12.58 ±0.82) mmHg(1 mmHg=0.133kPa)]比较,CH组大鼠RVSP和mRVP均明显升高[(50.46±9.51)、(21.66±1.85) mmHg,P＜0.05];CH组右心室肥厚指数(0.56±0.05)比常氧组(0.36±0.04)明显升高(P＜0.05);CH组静脉血管腔占血管区域的比值为(48.62±13.61)％,与常氧组(66.16±8.72)％相比显著降低(P＜0.05),而CH组静脉WT％ (16.43±5.08)％与NC(7.23 ±0.71)％相比显著增加(P＜0.05);此外CH组大鼠肺静脉平滑肌组织和细胞PPARγ蛋白相对常氧组的表达量分别为(52.95±3.83)％和(59.38±17.12)％,差异有统计学意义(P＜0.05).结论 CHPH大鼠模型RVSP、mRVP、右心室肥厚指数均升高,同时伴有肺小静脉重塑,其机制可能与低氧诱导静脉PPARγ蛋白表达降低有关.     

间歇性低压低氧预适应延缓大鼠低氧性肺动脉高压发展并改善肺动脉舒张

目的 观察间歇性低压低氧预适应对大鼠低氧性肺动脉高压（HPH）及肺动脉舒张功能的影响。方法 将24只雄性SD大鼠随机分为:对照组、HPH组、间歇性低压低氧预适应组,每组8只。对照组动物常规饲养10周;HPH组动物先在同一室内常规饲养6周,然后按低压低氧法建立HPH模型（给予持续低压低氧4周）;间歇性低压低氧预适应组动物先给予预适应实验:HPH 1周,再放置同一室内常规饲养1周,如此重复循环3个周期共6周,然后按低压低氧法建立HPH模型（方法同HPH组）。分组模型建立后,用右心导管法测定肺动脉平均压（mPAP）、右心室平均压（mRVP）;称重测量右心室/（左心室+室间隔）〔RV/(LV+S)〕、右心室/体质量（RV/BW）;HE染色高倍镜下观察肺小动脉显微结构改变;取大鼠左、右肺动脉干制备血管环,行离体血管灌流实验,观察不同浓度乙酰胆碱和硝普钠的舒张血管作用。结果 与对照组比,HPH组大鼠的mPAP、mRVP、RV/(LV+S)、RV/BW均显著增高（P<0.01）;病理切片显示低氧后大鼠肺动脉平滑肌和弹力纤维层增生,血管壁增厚,管腔狭窄、变形;且低氧后大鼠肺动脉血管环对乙酰胆碱的舒张作用显著降低（P<0.01）。与HPH组比,经间歇性低压低氧预适应处理的大鼠mPAP、mRVP、RV/(LV+S)、RV/BW均显著降低（P<0.05）;病理切片显示肺动脉平滑肌和弹力纤维层增生及血管壁增厚有所缓解;且肺动脉血管环对乙酰胆碱的舒张作用显著增强（P<0.05）。结论 间歇性低压低氧预适应可增强大鼠肺动脉对低压低氧环境的耐受能力,延缓肺动脉高压和右心重构的发展,并改善肺动脉内皮功能。     

低压低氧对SD大鼠肺动脉压及肺组织骨桥蛋白表达的影响

目的观察不同时间低压低氧刺激下SD大鼠肺动脉压及肺组织骨桥蛋白(OPN)表达的变化,探讨OPN在肺动脉高压发病机制中的作用。方法将30只SD大鼠随机分成5组:对照组(海拔2 260 m)、低压低氧(低压氧舱模拟5 000 m海拔)1天组、7天组、14天组、21天组,每组动物均测定平均肺动脉压(m PAP)和右心室肥厚指数[RV/(LV+S)];并分别采用RT-PCR法检测各组大鼠肺组织中OPN m RNA的水平,Western blot技术检测各组大鼠肺组织中OPN蛋白表达水平。结果低压低氧1天、7天、14天、21天组动物m PAP均高于对照组(P0.05),1天、7天、14天组呈逐渐增高趋势、21天组m PAP下降,差异有显著性(P0.05);低压低氧7天组、14天组、21天组动物呈现随低氧时间延长RV/(LV+S)逐渐增高的趋势、均高于对照组和1天组(P0.05),但1天组、7天组和对照组间差异无显著性(P0.05);RT-PCR法和Western blot法结果显示低压低氧1天、7天、14天、21天组动物肺组织中OPNm RNA、OPN蛋白表达水平与对照组比较均增高(P0.05)。结论低压低氧刺激可使m PAP和RV/(LV+S)增高并促进大鼠肺组织OPN的表达增高,因此OPN可能参与高原性心脏病形成中肺动脉压的增高和右心室重塑。     

慢性低氧所致肺动脉高压对大鼠肺动脉内蛋白激酶Cα的膜转位和蛋白表达量的影响

目的 通过观察慢性低氧所致肺动脉高压对大鼠肺动脉内蛋白激酶Cα(PKCα)的膜转位和蛋白表达量的影响,初步探讨PKCα在慢性低氧诱导大鼠肺动脉高压的发生和发展过程中所起的作用.方法 采用慢性常压低氧[氧浓度(10±0.1)％]大鼠肺动脉高压模型,将雄性SD大鼠随机分为正常对照组、低氧1d、3d、7d、14 d和21d组,检测大鼠右心室收缩压(RVSP)和右心室肥厚指数(RVHI),肺组织苏木精-伊红(HE)染色,应用蛋白免疫印迹和免疫组织化学的方法检测PKCα膜转位和蛋白表达水平的变化.结果 ①低氧1d、3d、7d、14 d和21d组与正常对照组相比,RVSP和RV/(LV+S)比值均明显增加(P＜0.05),低氧暴露3d、7d、14 d和21 d后大鼠肺动脉壁明显增厚;②PKCα的蛋白表达量在慢性低氧1d、3d、7d和14 d后比正常对照组明显下降(P＜0.05).结论 PKCα蛋白表达量的下调可能参与了慢性低氧诱导的大鼠肺动脉高压的发生和发展过程.     

波生坦对慢性低氧性肺动脉高压大鼠右心室肥厚及缝隙连接蛋白(Cx)43表达的影响

目的:研究波生坦(bosentan,BST)对慢性低压低氧性肺动脉高压(HPH)大鼠右心室肥厚及缝隙连接蛋白43(Cx43)表达量的影响。方法:将24只实验动物随机分为正常组、HPH组、安慰剂组和BST治疗组,每组各6只。正常组:常压常氧下饲养6周;其他3组大鼠置于低压低氧仓内8h/d,共6周,从第4周开始,每天给BST治疗组大鼠BST(100mg/kg)灌胃,安慰剂组生理盐水灌胃。6周后,所有大鼠测定血流动力学指标:如平均肺动脉压力(mPAP)、右心室收缩压(RVSP)、右心室收缩压上升最大速率(dp/dtmax),以及右心室肥厚度[如右心室质量/(左心室质量+室间隔质量),RV/(LV+S)]和右心室质量/体质量(RW/BW)。收集动脉血检测血浆内皮素-1(ET-1)和一氧化氮(NO)水平。Masson染色观察心肌胶原纤维容积百分比的变化,免疫组化染色法和Westernblot观察Cx43的变化。结果:BST治疗组大鼠的mPAP、RVSP、RV/(LV+S)、RW/BW及心肌胶原纤维容积百分比均较HPH组显著降低(P0.05),但血浆NO、ET-1的水平和心肌Cx43表达量显著升高(P0.05)。结论:BST在降低肺动脉压力的同时,还可抑制右心室肥厚和Cx43表达量的降低。     

H_2S对低氧性肺动脉高压大鼠肺组织BaxmRNA、Bcl-2mRNA表达的影响

目的研究H2S对大鼠低氧性肺动脉高压及凋亡相关基因BaxmRNA、Bcl-2mRNA表达的影响,探讨其在低氧性肺动脉高压发病中的作用。方法将30只雄性Wistar大鼠随机分为三组:常氧对照组、低氧组及低氧+Na HS组(腹腔注射Na HS并进行低氧处理)。常压间歇低氧法建立大鼠低氧性肺动脉高压模型,右心导管法检测平均肺动脉压(m PAP);分别称量大鼠右心室(RV)和左心室加室间隔(LV+S)的质量,计算出右心室肥厚指数RV/(LV+S);HE及弹力纤维+VG染色光镜下观察肺血管形态及肺小动脉平滑肌结构,弹力纤维、肌纤维及胶原纤维增生情况;RT-PCR方法检测BaxmRNA、Bcl-2mRNA在肺组织中的表达。结果 1低氧各组较对照组体重明显减轻(P0.05),但低氧+Na HS组明显高于低氧组(P0.05),造模前各组大鼠体重无差别(P0.05)。2低氧各组较对照组m PAP明显升高(P0.05)、RV/(LV+S)明显增加(P0.05)。低氧+Na HS组较低氧组m PAP明显降低(P0.05),RV/(LV+S)明显减少(P0.05)。3光镜下观察,对照组肺动脉管壁较薄,薄厚均匀,管腔较大。内弹力膜呈平缓波浪状,管壁层次结构清晰;低氧组肺小动脉平滑肌增生,胶原纤维增多,管壁增厚,管腔狭窄。内弹力膜增厚,外膜胶原纤维增生、沉积,外弹力膜也增厚,内外弹力板间距离均增宽;中膜平滑肌细胞也增生明显,管壁增厚,管腔明显变小,管周水肿。低氧+Na HS组较低氧组上述表现有所缓减。4低氧各组较对照组肺组织BaxmRNA表达均显著降低,Bcl-2 mRNA表达均显著增加(P0.05)。低氧+Na HS组较低氧组肺组织BaxmRNA表达显著升高,Bcl-2mRNA表达明显降低(P0.05),低氧+Na HS组较对照组大鼠肺组织BaxmRNA、Bcl-2 mRNA表达无统计学差异(P0.05).结论 H2S可以调节低氧性肺动脉高压细胞大鼠肺组织凋亡相关基因BaxmRNA、Bcl-2mRNA的表达,缓解低氧性肺血管重建,对低氧性肺动脉高压的发病起到保护作用。     

安立生坦与波生坦对低氧性肺动脉高压大鼠右心室重构影响的比较研究

目的:比较安立生坦(ambrisentan)与波生坦(bosentan)对低氧性肺动脉高压大鼠(HPH)右心室重构的影响。方法:40只SD大鼠随机分成5组:正常对照组、模型组、安立生坦组、波生坦组、安慰剂组,每组8只。正常对照组于自然环境中饲养4周,其他组置于低压低氧舱中(8 h/d)饲养4周。从低氧开始第3周起,安立生坦组、波生坦组和安慰剂组大鼠每天进舱前依次分别给予安立生坦(5 mg/kg)、波生坦(125 mg/kg)及生理盐水(2 ml)灌胃,共两周。实验结束后,测定平均肺动脉压(mPAP)和右心室收缩压(RVSP);计算右心室肥厚指数[RV/(LV+S)]及右心室质量/体质量(RW/BW)。右心室心肌以HE染色后,观察其形态学变化,以Masson染色后观察心肌胶原纤维容积分数(CVF)的变化。结果:与模型组和安慰剂组相比,安立生坦组和波生坦组的mPAP、RVSP、RV/(LV+S)、RW/BW、CVF值明显降低(P<0.05),安立生坦组和波生坦组相比,上述指标的差异无明显的统计学意义。HE染色切片显示,模型组和安慰剂组大鼠心肌细胞肥大,安立生坦组和波生坦组可基本恢复至正常组状态。结论:安立生坦与波生坦能显著降低HPH大鼠的肺动脉压力,抑制右心室肥厚及纤维化。安立生坦与波生坦相比,对HPH大鼠右心室重构的影响无明显差别。     

白藜芦醇苷对慢性低氧性肺动脉高压大鼠肺内突变型p53基因表达的影响

目的研究白藜芦醇苷（PD）对慢性低氧性肺动脉高压（CHPH）大鼠肺内突变型p53基因表达的影响。方法将SD大鼠随机分为对照组、低氧组和低氧＋PD治疗组。观察PD对CHPH大鼠平均肺动脉压（mPAP）、右心室肥厚指数[右室／左室＋室间隔（R／L＋S）]、肺血管形态学指标、突变型p53基因表达的影响。结果21d后，低氧组mPAP、R／（L＋S）、肺血管管壁面积占血管总面积的百分比、管壁厚度占血管外径的百分比及突变型p53基因表达明显升高，肺血管管腔面积占血管总面积的百分比明显降低；低氧＋PD组上述变化得到抑制或减轻。结论PD可有效降低肺动脉压，延缓大鼠CHPH进程，其机理可能与抑制突变型p53基因表达及细胞增殖，从而有效抑制肺血管重建有关。     

血管内皮生长因子和内皮素在低氧性肺血管重建中的作用

目的探讨血管内皮生长因子(VEGF)和内皮素(ET)-1在低氧性肺动脉高压(HPH)及其肺血管重建中的作用,并观察钾通道开放剂(pinacidil)对HPH的防治作用及对VEGF和ET-1的影响.方法Wister大鼠46只,随机分为3组,对照组15只,低氧组16只,治疗组15只.缺氧组和治疗组大鼠缺氧[氧浓度为(10.0±0.5)%]4周,每天缺氧8h,其中治疗组大鼠于每天缺氧前腹腔注射pinacidil3mg/kg.缺氧4周后测定各组大鼠血清VEGF和血浆ET-1水平、平均肺动脉压(mPAP)、右心室(RV)/[左心室(LV)+室间隔(S)]比值及肺小动脉病理及其形态计量学.结果(1)缺氧组大鼠血清VEGF[(118.73±55.40)ng/L]和血浆ET-1[(221.2±56.2)ng/L]水平明显高于对照组(P＜0.01);缺氧组较对照组mPAP升高,RV/(LV+S)比值增高,肺小动脉血管壁显著增厚,管腔明显狭窄.(2)治疗组大鼠血清VEGF[(78.20±16.45)ng/L]和血浆ET-1[(181.6±30.5)ng/L]水平明显低于缺氧组(P＜0.01);治疗组较缺氧组mPAP下降(P＜0.01),肺小动脉血管壁增厚、管腔狭窄等明显减轻,但治疗组上述各指标仍未完全恢复到对照组水平.结论VEGF和ET-1在HPH及其肺血管重建中发挥重要作用,钾通道开放剂对HPH及其肺血管重建具有一定的逆转作用.     

肝素对低氧诱导肺动脉高压大鼠肺血管外膜重塑干预作用的研究

目的 探讨肝素对低氧诱导肺动脉高压(PAH)大鼠肺动脉外膜重塑的干预作用及机制. 方法 将60只健康雄性SD大鼠随机分为A、B、C三组,各20只;A组正常饲养,B组作低氧处理4周,C组作低氧处理4周后给予肝素处理.测定各组大鼠平均肺动脉压(mPAP)、右心室肥厚指数[RV/(LV S)]、PaCO2和PaO2.用免疫组化SP法检测肺动脉外膜巨噬细胞及其单核细胞趋化蛋白-1(MCP-1);用RT-PCR一步法检测肺组织中的MCP-1mRNA. 结果 B组mPAP、RV/(LV S)、PaCO2显著高于A组(P<0.05),C组显著低于B组(P<0.01),而PaO2则相反.肺动脉外膜单视野平均巨噬细胞数目(MAM)、巨噬细胞MCP-1蛋白及肺组织MCP-1 mRNA的表达B组显著高于A组(P<0.05),C组显著低于B组(P<0.01). 结论 MCP-1可能参与了缺氧诱导的肺动脉外膜重塑,促进了PAH的发生、发展.肝素封闭了MCP-1的作用,抑制肺血管结构外膜重建,减轻肺动脉高压.     

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.