勃起功能障碍可能是心血管疾病的信号

近期一项调查研究显示，出现勃起功能障碍的老年健康男子可能存在隐性心血管疾病。共有8063名55岁以上无心血管疾病的美国男子参加了该项队列研究，试验初始时4247人具有正常勃起功能。     

Exogenous advanced glycosylation end products induce diabetes-like vascular dysfunction in normal rats: a factor in diabetic retinopathy

BACKGROUND. Diabetic retinopathy has been shown to be directly associated with the degree and duration of hyperglycemia, and advanced glycosylation end products (AGEs) have been implicated in this pathological process. The purpose of the experiments reported here was to study the effect of AGE deposition on retinal vascular damage which leads to diabetic retinopathy. METHODS. Intravenous injection of exogenous AGEs was used to treat wild-type non-diabetic Sprague-Dawley rats. One of the two retinal slides from each animal was treated using immunohistochemical staining to label retinal vascular AGE deposition, the other H&E staining for counting of capillary pericytes. The results were compared with the findings in untreated wild-type and diabetic controls and in rats treated with unmodified rat serum albumin (RSA). RESULTS. After 2 weeks of continuous treatment, AGEs were identified in the retinal vascular tissue of the AGE-RSA-injected group. The average number of retinal capillary pericytes per 10x100 microscope power field was 4.313+/-0.34 (mean +/- SD) in the AGE-RSA-injected group, compared with 5.798+/-0.481 in the control group ( P<0.01). CONCLUSION. These experiments demonstrate that AGEs, independent of other metabolic factors, can induce vascular change resembling that of diabetic retinopathy.     

Insulin reduces the BOLD response but is without effect on the VEP during presentation of a visual task in humans.

Functional magnetic resonance imaging (fMRI) based on blood oxygen level-dependent (BOLD) contrast has become an invaluable tool in the assessment of in vivo neuronal activation. Quantification of the BOLD response is determined by the hemodynamic and metabolic changes that occur in response to brain stimulation. However, these changes may vary by changes in insulin, a hormone known to be vasoactive in some tissues. To determine if insulin has an effect on fMRI, we measured the BOLD response to a visual stimulus in five normal volunteers in which insulin was first suppressed and then brought to a high physiological concentration. In addition, we also examined the effect of insulin on activation of the visual cortex as measured by the visual-evoked potential (VEP). We found that the BOLD response measured in the presence of insulin (serum insulin=236+/-29 pmol/L) was significantly lower (P<0.001) than that measured in its absence (serum insulin=8+/-2 pmol/L). Insulin was without effect on P100 amplitude or latency acquired in the presence or absence of insulin in 28 subjects using the same stimulus as that used for the fMRI experiments. Our observations suggest that insulin may have effects on cerebral blood flow and/or metabolism that affect the BOLD signal that are independent of its effects on neuronal activation identified by event related potentials (ERP). These findings highlight the complexity that must be considered when interpreting differences in fMRI responses between groups of subjects that differ in insulin concentration and/or insulin sensitivity.     

Maplets for correspondence-based object recognition.

We present a correspondence-based system for visual object recognition with invariance to position, orientation, scale and deformation. The system is intermediate between high- and low-dimensional representations of correspondences. The essence of the approach is based on higher-order links, called here maplets, which are specific to narrow ranges of mapping parameters (position, scale and orientation), which interact cooperatively with each other, and which are assumed to be formed by learning. While being based on dynamic links, the system overcomes previous problems with that formulation in terms of speed of convergence and range of allowed variation. We perform face recognition experiments, comparing ours to other published systems. We see our work as a step towards a reformulation of neural dynamics that includes rapid network self-organization as essential aspect of brain state organization.     

微波快速过氧化物酶染色法与灌注法用于微循环形态学研究之比较

以健康Ｗｉｓｔａｒ大白鼠为材料，对微波快速内源性过氧化物酶染色与灌注法显示微血管的方法进行了对比研究。结果，过氧化物酶组织化学法具有不用灌注，操作简单，所用时间短，对血管无扩张、破裂等人为改变的特点，保持了微血管真实的自然形态和管径大小，可以定量或半定量地判定组织器官活体时的血液循环状况。可以用于人及动物的大脑、脊髓、皮肤、耳及食管等组织内微血管形态学研究和定量分析。并对过氧化物酶显示微血管的原理和微波辐射促进染色的原理及特点进行了分析、讨论。     

Serum creatine kinase B subunit in patients with renal cell carcinoma.

We determined the serum levels of the creatine kinase B subunit (CK-B) by an enzyme immunoassay method in patients with renal cell carcinoma (RCC) and benign renal diseases. Eighteen of 76 patients with RCC (24%) had elevated serum CK-B levels. The positive rates were 29% in stage I, 13% in stage II, 15% in stage III, and 27% in stage IV. In all 9 patients whose serum CK-B levels were serially measured and had been elevated before operation, the CK-B levels were reduced to the normal range after nephrectomy. These findings indicate that serum CK-B is a useful biomarker for monitoring the clinical course for a limited number of RCC patients, but is not a marker for diagnosis and staging. Concentrations of CK-B in RCC tissues were significantly lower than those of normal kidney. A high rate of cell turnover in tumor tissues might entail the higher level of serum CK-B in patients with RCC.     

格林—巴利综合征患者血清和脑脊液中的抗硫脂抗体

探讨抗硫脂抗体与格林－巴利综合征（ＧＢＳ）的关系。方法采用固相酶联免疫吸附法对急性期ＧＢＳ患者血清和脑脊液（ＣＳＦ）中抗硫脂ＩｇＧ和ＩｇＭ抗体进行检测。结果ＧＢＳ患者血清和ＣＳＦ中抗硫脂ＩｇＧ及ＩｇＭ抗体的阳性率均明显高于正常对照组；血清中抗硫脂ＩｇＭ抗体滴度与标本收集时患者发病天数呈负相关（Ｐ＜０．０５），而血清中抗硫脂ＩｇＧ抗体滴度与临床分级（Ｐ＜０．０１）、ＣＳＦ中抗硫脂ＩｇＧ抗体滴度（Ｐ＜０．０１）呈正相关；血清中抗硫脂ＩｇＧ或ＩｇＭ阳性的ＧＢＳ患者，体检时有不同程度的感觉障碍患者为５６％，而血清中抗硫脂抗体阴性患者仅为１６％，两者之间差异有显著意义（Ｐ＜０．０５）。结论抗硫脂抗体可能在ＧＢＳ的病理过程中起重要作用     

神经梅毒的临床特征与诊断分析

目的：分析神经梅毒的分型和临床特征及提供早期诊断依据。方法：回顾性分析经临床和实验室检查确诊的18例神经梅毒病人的有关临床资料。结果：神经梅毒的临床特征包括：(1)急性、亚急性起病为主；(2)临床以间质型，尤其是以脑卒中起病常见，症状元特异性；(3)血清学检查以梅毒螺旋体血凝试验(TPHA)及快速血浆反应素试验(RPR)特异性较高；(4)脑脊液检查表现为压力增高(42．9％)、蛋白增高(81．2％)及细胞数增高(56．3％)；(5)头颅CT、MRI表现与高血压、动脉硬化所致脑梗死不同，为多发、散在病灶。结论：神经梅毒早期误诊率高，临床表现与分型密切相关，实验室及影像学检查是诊断的重要依据。