Voluntary and involuntary attention affect face discrimination differently

Do voluntary (endogenous) and involuntary (exogenous) attention have the same perceptual consequences? Here we used fMRI to examine activity in the fusiform face area (FFA--a region in ventral visual cortex responsive to faces) and frontal-parietal areas (dorsal regions involved in spatial attention) under voluntary and involuntary spatial cueing conditions. The trial and stimulus parameters were identical for both cueing conditions. However, the cue predicted the location of an upcoming target face in the voluntary condition but was nonpredictive in the involuntary condition. The predictable cue condition led to increased activity in the FFA compared to the nonpredictable cue condition. These results show that voluntary attention leads to more activity in areas of the brain associated with face processing than involuntary attention, and they are consistent with differential behavioral effects of attention on recognition-related processes.     

The fusiform face area is not sufficient for face recognition: evidence from a patient with dense prosopagnosia and no occipital face area

We tested functional activation for faces in patient D.F., who following acquired brain damage has a profound deficit in object recognition based on form (visual form agnosia) and also prosopagnosia that is undocumented to date. Functional imaging demonstrated that like our control observers, D.F. shows significantly more activation when passively viewing face compared to scene images in an area that is consistent with the fusiform face area (FFA) (p < 0.01). Control observers also show occipital face area (OFA) activation; however, whereas D.F.'s lesions appear to overlap the OFA bilaterally. We asked, given that D.F. shows FFA activation for faces, to what extent is she able to recognize faces? D.F. demonstrated a severe impairment in higher level face processing--she could not recognize face identity, gender or emotional expression. In contrast, she performed relatively normally on many face categorization tasks. D.F. can differentiate faces from non-faces given sufficient texture information and processing time, and she can do this is independent of color and illumination information. D.F. can use configural information for categorizing faces when they are presented in an upright but not a sideways orientation and given that she also cannot discriminate half-faces she may rely on a spatially symmetric feature arrangement. Faces appear to be a unique category, which she can classify even when she has no advance knowledge that she will be shown face images. Together, these imaging and behavioral data support the importance of the integrity of a complex network of regions for face identification, including more than just the FFA--in particular the OFA, a region believed to be associated with low-level processing.     

人参Rb组皂苷对犬实验性心肌梗死的保护作用

目的：研究人参Ｒb组皂苷对犬实验性心肌缺血的保护作用。方法：通过结工冠状动脉前降支（ＬＤＡ）产生急性心肌梗死模型,从心肌梗死面积（ＭＩＳ）及血清酶学变化观察人参Ｒb组皂苷的抗心肌缺血作用,并从心肌代谢及自由基损伤等角度分析其可能的作用机制。结果人参Ｒb组皂苷２５,５０mg/kg经十二指肠给药,对ＬＡＤ急悸阻断６h犬,能明显缩小ＭＩＳ,降低血清肌酸磷酸激酶（ＣＫ）及乳酸脱氢酶（ＬＤＨ）活性,亦能明显降低血清游离脂肪酸（ＦＦＡ）及过氧化脂质（ＬＰＯ）含量,提高超氧化物歧化酶（ＳＯＤ）活性。结论：人参Ｒb组皂苷对急性缺血心肌产生明显保护作用,作用机制可能与其纠正心肌缺血时ＦＦＡ代谢紊乱及对抗氧自由基引发的脂质过氧化反应,增强体内抗氧化酶活性等有关。     

Vogt-小柳原田综合征1例报告并文献复习

目的：探讨Vogt‐小柳原田综合征的发病机制、临床表现、诊断及治疗措施。方法对1例以中枢神经系统表现为首发症状的小柳原田综合症患者的诊疗经过进行分析。结果患者具有葡萄膜炎及中枢神经系统症状、体征,结合相关检查结果,采用激素治疗,预后良好。结论 Vogt‐小柳原田综合征是一个累计多个系统的免疫性疾病,临床表现多样,误诊漏诊率高,中枢神经系统表现与脑膜脑炎相似。采用视力、眼底检查、荧光素眼底血管造影（FFA ）等有助于早期诊断。应尽早行激素治疗以缩短病程,改善预后,减少并发症的发生。     

大黄素、小檗碱对HepG2细胞胰岛素抵抗的预防作用研究

目的：研究大黄素、小檗碱对HepG2细胞产生胰岛素抵抗的预防作用及机制。方法：首先用MTT法筛选大黄素、小檗碱作用于HepG2细胞的实验浓度,然后用软脂酸诱导HepG2细胞,同时分别加入大黄素、小檗碱干预,并设正常组、对照组进行比较,通过葡萄糖氧化酶法、蒽酮法、RT-PCR法,观察大黄素、小檗碱对HepG2细胞上糖代谢及瘦素长型受体、短型受体mRNA表达水平的影响。结果：对照组成为具有胰岛素抵抗的HepG2细胞,且细胞上瘦素长型及短型受体mRNA的表达水平较正常组显著下降（P < 0.01）;而大黄素、小檗碱组培养液中葡萄糖含量、细胞内糖原含量以及细胞上瘦素长型及短型受体mRNA的表达水平较正常组无明显改变（P > 0.05）。结论：大黄素、小檗碱均能预防HepG2细胞产生胰岛素抵抗,这一作用与它们影响 HepG2细胞上糖代谢及瘦素受体mRNA表达水平有关。     

FFA在Eales病激光治疗中的作用探讨

目的探讨荧光素眼底血管造影(FFA)在视网膜静脉周围炎(Eales病)激光治疗中的作用。方法按病例选择标准筛选60例(108眼)经临床确诊为Eales病患者,随机分为研究组和对照组。研究组用FFA检查后选择眼底病变区域行激光光凝。对照组不经FFA检查,直接行视网膜光凝。6个月后两组病例均用FFA检查视网膜、血管病变是否好转,比较治疗前后视力、眼底变化、视野改变,评价治疗效果。结果研究组33例58眼Eales病患眼治疗有效54眼(93.1%),无效4眼(6.9%)。对照组27例50眼Eales病患眼治疗有效34眼(68.0%),无效16眼(32.0%)。研究组58眼激光光凝后均无视野改变,对照组50眼激光光凝后均有不同程度视野缩小。结论依据FFA检查对Eales病激光光凝,治疗效果优于不经FFA检查直接行视网膜光凝。FFA为进一步探讨Eales病的发病机理,为临床治疗Eales病提供重要的指导依据。     

糖化血清蛋白及游离脂肪酸在2型糖尿病患者血清中的变化分析

目的:通过对2型糖尿病患者空腹糖化血清蛋白(GSP)和空腹、餐后2h的血糖及游离脂肪酸(FFA)浓度的测定,分析其变化情况及意义。方法:选取2型糖尿病患者34例,正常对照组31例,采用葡萄糖己糖激酶法测定血糖浓度;酮胺氧化酶法测定GSP的浓度;酶比色法测定FFA的浓度。结果:2型糖尿病组空腹GSP、FFA及餐后2h的血糖浓度与正常对照组相比较,差异有显著性(P<0.05);2型糖尿病组空腹及餐后2h的血糖浓度与FFA呈正相关(r=0.8722、r=0.8553,P<0.01),与GSP呈正相关(r=0.9277、r=0.9091,P<0.01);餐后FFA虽较餐前略有下降,但无显著差异(P>0.05)。结论:GSP和FFA浓度的测定对2型糖尿病的监控具有重要价值。     

The mechanism of action of clofibrate and tetranicotinoylfructose (Bradilan) on the kinetics of plasma free fatty acid and triglyceride transport in type IV and type V hypertriglyceridaemia

Abstract. The kinetics of plasma free fatty acid and triglyceride transport were assessed in 20 patients with idiopathic hypertriglyceridaemia. These patients were subdivided according to lipoprotein pattern into Type IV and Type V patients. The effects of clofibrate therapy on plasma free fatty acid and triglyceride kinetics were assessed in these patients. Clofibrate produced a marked reduction in serum triglyceride associated with a significant reduction in triglyceride turnover as well as enhancement of triglyceride clearance. The reduction in triglyceride concentration produced by clofibrate was found to correlate with the reduction in free fatty acid turnover indicating that this drug decreased the availability of free fatty acid turnover indicating that this drug decreased the availability of free fatty acids for hepatic esterification. Clearance of endogenous plasma triglyceride was markedly enhanced in those patients in whom it was markedly impaired before treatment.—Having discontinued clofibrate for six weeks the same patients received bradilan (tetranicotinoylfructose) and kinetic measurements were repeated. It was evident that bradilan had a greater hypotriglyceridaemic effect than clofibrate in both groups of patients. The effect of bradilan was the result of inhibition of free fatty acid turnover and consequently a marked reduction in triglyceride turnover. Bradilan, unlike clofibrate, did not affect the mechanisms responsible for the clearance of plasma triglycerides.