Enhanced stimulus-reward learning by intra-amygdala administration of a D3 dopamine receptor agonist

The amygdala is considered to be a critical neural substrate underlying the formation of stimulus-reward associations, and is known to receive substantial innervation from dopaminergic neurons located within the ventral mesencephalon. However, relat- ively little is known about the function of the mesoamygdaloid dopamine projection in stimulus-reward learning. Recently, we have found post-session intra-amygdala microinjections of d-amphetamine to enhance appetitive Pavlovian conditioning as assessed in a discriminative approach task. In the present study, we have examined the effects of dopamine receptor agonists possessing relative selectivity for the D₁, D₂ and D₃ receptor subtypes in order to examine more fully the role of the mesoamygdaloid dopamine projection in stimulus-reward learning. Thus, subjects were trained to associate an initially neutral stimulus (CS⁺) with 10% sucrose reward (US). A second, control stimulus (CS⁻) was also presented but never paired with sucrose reward. In order to measure specifically the conditioned response to CS⁺/CS⁻ presentation, responding during CS and US presentations was measured separately. Immediately following each training session, subjects received bilateral intra-amygdala infusion of 0.1, 1 or 10 nmol/side of SKF-38393, quinpirole or 7-OH-DPAT. Infusions of SKF-38393 or quinpirole were without effect on CS⁺ approach. However, post-session intra-amygdala infusions of 7-OH-DPAT enhanced selectively CS⁺ approach in a dose-dependent fashion. No dose of any drug affected CS⁻approach, US behaviours, or measures of extraneous behaviour. Subsequent acquisition of a novel conditioned instrumental response was also unaffected. Thus, the present data indicate a selective involvement of the D₃ dopamine receptor subtype in the modulation of stimulus-reward learning by the mesoamygdaloid dopamine projection. Received: 12 December 1996 / Final version: 9 April 1997     

Improved intracranial lesion characterization by tissue segmentation based on a 3D feature map

Our aim was to develop an accurate multispectral tissue segmentation method based on 3D feature maps. We utilized proton density (PD), T₂-weighted fast spin-echo (FSE), and T₁-weighted spin-echo images as inputs for segmentation. Phantom constructs, cadaver brains, an animal brain tumor model and both normal human brains and those from patients with either multiple sclerosis (MS) or primary brain tumors were analyzed with this technique. Initially, misregistration, RF inhomogeneity and image noise problems were addressed. Next, a qualified observer identified samples representing the tissues of interest. Finally, k-nearest neighbor algorithm (k-NN) was utilized to create a stack of color-coded segmented images. The inclusion of T₁ based images, as a third input, produced significant improvement in the delineation of tissues. In MS, our 3D technique was found to be far superior to that based on any combination of 2D feature maps (P < 0.001). We identified at least two distinctly different classes of lesions within the same MS plaque, representing different stages of the disease process. Further, we obtained the regional distribution of MS lesion burden and followed its changes over time. Neuropsychological aberrations were the clinical counterpart of the structural changes detected in segmentation. We could also delineate the margins of benign brain tumors. In malignant tumors, up to four abnormal tissues were identified: 1) a solid tumor core, 2) a cystic component, 3) edema in the white matter, and 4) areas of necrosis and hemorrhage. Subsequent neurosurgical exploration confirmed the distribution of tissues as predicted by this analysis.     

Hemorrhagic fever with renal syndrome virus infection in livers studied by in situ hybridization and immunohistochemistry

ＨｅｍｏｒｒｈａｇｉｃｆｅｖｅｒｗｉｔｈｒｅｎａｌｓｙｎｄｒｏｍｅｖｉｒｕｓｉｎｆｅｃｔｉｏｎｉｎｌｉｖｅｒｓｓｔｕｄｉｅｄｂｙｉｎｓｉｔｕｈｙｂｒｉｄｉｚａｔｉｏｎａｎｄｉｍｍｕｎｏｈｉｓｔｏｃｈｅｍｉｓｔｒｙＹａｎｇＳｈｏｕｊｉｎｇ（杨守京）；Ｌ...     

病毒性肝炎60例临床与病理分析

对６０例病毒性肝炎患者进行肝穿刺活检，结果发现，临床与病理诊断的符合率为４６．６％，其中，急性肝炎的诊断符合率最低（２３．８％），慢性迁延型肝炎（慢迁肝）为４４．８％；ＨＢｓＡｇ阳性首次发病的患者中，急性乙型肝炎仅为１１．２％（２／１８）；临床诊断的慢性活动型肝炎（慢活肝）仅为病理检出的２５．７％（９／３５）；肝炎患者中脾肿大，凝血酶元时间延长、Ａ／Ｇ值＜１．２、抗ＨＢｃＩｇＭ阳性可作为慢活肝与慢迁肝鉴别的重要指标。这些对提高病毒性肝炎临床分型诊断的准确率及指导临床治疗有意义。     

胃复春片对慢性胃病患者窦D细胞的影响

目的：探讨胃复春片治疗慢性胃病患者前后生长抑素内分泌细胞(D细胞)数量变化。方法：用免疫组化酶链亲合素过氧化酶复合技术(SABC)对患者治疗前后胃粘膜组织的D细胞染色，观察治疗前后D细胞的形态和数量变化。结果：经胃复春片治疗后，患者胃窦粘膜D细胞阳性数及强阳性率均明显下降，有显著意义。结论：胃复春片对慢性胃病患者生长抑素D细胞有调整作用。     

血清前－S_2蛋白检测的临床意义

采用ＥＬＩＳＡ法检测１０４例各类型乙型肝炎（乙肝）患者的血清前－Ｓ２抗原（Ｐｒｅ－Ｓ２Ａｇ）及其抗体（Ｐｒｅ－Ｓ２Ａｂ），结果表明，Ｐｒｅ－Ｓ２Ａｇ的出现与ＨＢｓＡｇ、ＨＢｅＡｇ、ＨＢｃＡｂ呈显著相关性（Ｐ值均＜０．００５），主要见于乙肝急性期及慢性乙肝患者，说明病毒复制活跃、传染性强。而Ｐｒｅ－Ｓ２Ａｂ阳性仅见于急性乙肝恢复期。     

HCVRNA阳性的丙型肝炎诊断和治疗探讨

HCVRNA阳性的丙型肝炎46例，均经临床和／或组织学确诊。治疗组24例用IFNa－nl或a－2b3×106IU，隔日一次；对照组22例用一般护肝药物。HCVRNA12周转阴率治疗组为83．3％，对照组为9．0％（P＜0．001）。ALT和AST复常率治疗组也优于对照组（P＜0．05）。随访观察满48周者治疗组15例中HCVRNA持续转阴11例（73．3％）．对照组5例均持续阳性。治疗组中5例做了Ⅰ～Ⅲ型HCV基因分型，结果均为Ⅱ型。同时对急、慢性丙型肝炎的发病过程和病理诊断作了讨论。     

巢式聚合酶链反应检测脑脊液中单纯疱疹病毒DNA

应用巢式聚合酶链反应(PCR)检测患者脑脊液(CSF)中单纯疱疹病毒1型(HSV-1)DNA。23例经鞘内HSV-1特异性IgG抗体检测阳性的“HSV-1型性脑炎(HSE)”中19例PCR阳性,4例阴性患者病程均超过1个月。22例IgG阴性的“散发性脑炎”中7例PCR阳性,此7例皆于发病1周内检查CSF,其中2例取材于发病当日。1周后复查7例患者,CSF PCR仍为阳性,IgG皆阴性,提示PCR适用于HSE的早期诊断。     

[H](+)S 14297: A novel, selective radioligand at cloned human dopamine D3 receptors

The selective dopamine D₃ receptor antagonist [³H](+)S 14297 ((+)-[7-(N,N-dipropylamino)-5,6,7,8-tetrahydro-naphtho(2,3b)dihydro,2,3-furane]), labelled to high specific activity (145 Ci/mmol), bound to cloned human dopamine D₃ receptors but displayed negligible binding to cloned human D₂ receptors. [³H](+)S 14297 exhibited rapid association and dissociation, high affinity saturable binding (K_d = 7.0 nM) and a competition binding profile highly correlated with that of [¹²⁵I]iodosulpride (r = 0.98).