Glucose availability regulates ghrelin‐induced food intake in the ventral tegmental area

Information about metabolic status arrives in the brain in the form of a complex milieu of circulating signalling factors, including glucose and fatty acids, ghrelin, leptin and insulin. The specific interactions between humoural factors, brain sites of action and how they influence behaviour are largely unknown. We have previously observed interactions between glucose availability and the actions of ghrelin mediated via the agouti‐related peptide neurones of the hypothalamus. In the present study, we examine whether these effects generalise to another ghrelin‐sensitive brain nucleus, the ventral tegmental area (VTA). We altered glucose availability by injecting mice with glucose or 2‐deoxyglucose i.p. to induce hyperglycaemia and glucopenia, respectively. Thirty minutes later, we injected ghrelin in the VTA. Glucose administration suppressed intra‐VTA ghrelin‐induced feeding. Leptin, a longer‐term signal of positive energy balance, did not affect intra‐VTA ghrelin‐induced feeding. 2‐Deoxyglucose and ghrelin both increased food intake in their own right and, together, they additively increased feeding. These results add support to the idea that calculation of metabolic need depends on multiple signals across multiple brain regions and identifies that VTA circuits are sensitive to the integration of signals reflecting internal homeostatic state and influencing food intake.     

空洞型肺癌的PET-CT影像特点分析

目的分析空洞型肺癌的PET-CT影像特点。方法回顾性分析35例经病理证实空洞型肺癌患者的PET-CT表现,分析不同病理类型空洞型肺癌间的差异及病理类型、空洞壁厚度最大径、肿瘤最大径对最大标准摄取值(maximum standardized uptake value,SUV max)的影响。结果35例患者中,鳞癌15例,腺癌20例,鳞癌组SUV max为13.51±4.73,显著大于腺癌组(8.50±4.27),P<0.05;而鳞癌组空洞壁厚度最大径及肿瘤最大径均显著大于腺癌组(P值分别为0.001、0.043),两者之间空洞最大径差异无统计学意义(P>0.05)。在空洞壁厚度最大径分组(<0.5 cm,0.5~1.5 cm,>1.5 cm)及肿瘤最大径分组(<3 cm、3~5 cm,>5 cm)中,SUV max差异有统计学意义(F=10.735,P<0.001;F=6.568,P=0.004)。结论18 F-脱氧葡萄糖(18 F-FDG)PET-CT对空洞型肺癌有较好的诊断价值,且SUV max与病理类型、空洞壁厚度最大径以及肿瘤最大径存在一定的关联。     

前期调糖对冠心病患者18F-FDG PET心肌代谢显像图像质量的影响

 目的 探讨前期调糖对冠心病(coronary heart disease,CHD)患者¹⁸F-FDG PET心肌代谢显像图像质量的影响。方法 选择131例年龄33～79岁,CHD患者,男121例,女10例,其中68例合并糖尿病(DM),采用空腹口服葡萄糖＋静脉注射胰岛素法调节血糖,测量其FBG、PBG、BG_注射、记录其高糖及胰岛素用量,之后行¹⁸F-FDG PET心肌代谢显像。图像质量评定采用盲法评定评分法。结果 131例中仅1例显像失败,显像成功率99.2%;将130例显像成功者按是否合并DM分析显示,不合并DM者易获得更佳的图像质量(P=0.002)。患者FBG及BG_注射对图像质量有影响,FBG和BG_注射较低者更易获得高质量的图像,差异有统计学意义(P均=0.000),而PBG和BG_差对最终图像质量无明显影响(P分别=0.191及0.283)。不合并DM组的患者胰岛素/高糖比值与图像质量无明显相关性(P=0.484),而合并DM组患者的胰岛素/高糖在不同图像质量组间有差异,图像质量更好组(评分3分)的胰岛素/高糖更高,差异有统计学意义(P=0.021)。结论 口服葡萄糖+静脉注射胰岛素法¹⁸F-FDG PET心肌代谢显像成功率高,影响图像质量的主要因素是患者FBG和BG_注射。     

18F-FDG PET/CT在胆管癌诊治中的应用

目的:探讨¹⁸F-FDG PET/CT在胆管癌术前诊断和术后疗效评估中的应用价值。方法:对25例胆管癌患者（术前7例,术后18例）进行¹⁸F-FDG PET/CT显像检查,测定病灶部位初次检查及延迟显像SUV_max,观察其表现及术后疗效。结果:PET/CT诊断胆管癌符合率100%,灵敏度95%,特异性90%。结论:¹⁸F-FDG PET/CT对胆管癌的诊断和术后疗效评估具有重要临床价值。     

18F-FDG PET、CT和血管造影在原发性肝癌TACE后随访的对比研究

目的:探讨18F-FDG PET、CT和血管造影对原发性肝癌TACE后残留及转移病灶的检出能力。材料与方法:80例经穿刺活检或手术病理证实的肝癌患者,其中高分化肝细胞癌20例、中分化肝细胞癌44例、低分化肝细胞癌11例、肝胆管细胞癌3例、肝腺癌2例。以临床随访6个月以上及部分病理结果为标准,回顾性分析TACE后1.5~2个月18F-FDG PET、CT和血管造影对肿瘤残留及转移病灶的显示情况。结果:80例患者肝内共104个病灶,经临床随访6个月以上及部分病理结果证实,有肿瘤残留病灶62个,PET正确检出56个,CT正确检出38个,血管造影正确检出58个;无肿瘤残留病灶42个,PET正确检出40个,CT正确检出40个,血管造影正确检出42个。PET和血管造影对肝癌TACE后肿瘤残留病灶检出的灵敏度和准确性分别为90.3%、92.3%和93.6%、96.2%,明显高于CT(61.3%、75.0%),差异显著(P<0.01)。同时PET检出了CT和血管造影无法发现的肝外转移病灶5例。结论:CT是肝癌TACE后最常用的随访方法,可以清晰显示碘油在病灶内的分布情况。18F-FDG PET显像能够更加准确的鉴别肿瘤存活,特别是CT无法明确的病变,而且对于肝外转移病灶的检出具有独特的优势。血管造影的诊断灵敏度、准确性最高,但是属于有创性检查。将多种影像学方法相结合,能够为临床提供更加可靠的定位和定性的诊断依据。     

钒酸钠降糖作用机理的研究

为探讨钒酸钠降糖作用的机理，对链脲佐菌素（ｓｔｒｅｐｔｏｚｏｔｏｃｉｎ，ＳＴＺ）致糖尿病大鼠饮用钒酸钠前后血糖、血脂、胰岛素水平以及骨胳肌细胞膜胰岛素受体和葡萄糖摄取进行了测定。结果表明，糖尿病大鼠经钒酸钠治疗４周后，在不通过刺激胰岛素分泌的情况下，能纠正糖脂代谢紊乱，并能显著改善骨胳肌葡萄糖摄取，但对其细胞膜受体数目及亲和性影响不明显。提示钒酸钠的类胰岛素作用可能与受体后效应即外周组织葡萄糖摄取增加利用有关。     

Activation of brain regions of rats during fever

The central nervous structures involved in febrile responses were investigated in conscious rats by means of the 2-deoxy-D-[14C]glucose autoradiographic technique. An intravenous injection of endogenous pyrogen prepared from rabbit white blood cells induced a significant rise in the rectal temperature of rats accompanied by a decrease in the skin temperature. According to autoradiographs, significant increases in metabolic activity were observed in the lateral preoptic area, posterior part of dorsomedial thalamus, posterior hypothalamus and the red nucleus during an induced fever. Because of the close relationship between metabolic activity and brain function, these regions are considered to compose the neural components directly or indirectly related with the febrile responses.     

Beneficial effect of residual anterograde flow on tissue viability as assessed by positron emission tomography in patients with myocardial infarction

With the advent of therapeutic interventions to restore bloodflow in patients with acute infarction, early identificationof salvageable myocardium has gained clinical importance. Itwas the purpose of this study to define regional blood flowand glucose metabolism in patients with acute myocardial infarctionas assessed by positron emission tomography (PET) and to correlatethese findings with coronary anatomy. In 15 patients blood flowas determined by N-13 ammonia was reduced in 37 left ventricularsegments. In 20 segments there was a similar decrease in FDGuptake, consistent with tissue necrosis. In contrast, 17 segmentswith reduced blood flow revealed maintained FDG uptake suggestingresidual viability in the electrocardiographically defined ‘infarctsegment’. PET viability and necrosis was significantlyassociated with presence or absence of anterograde flow in theinfarct artery. Evaluation of regional wall motion did not distinguishsegments with PET criteria for viability from segments withnecrosis. Thus, in patients without thrombolytic therapy duringevolving myocardial infarction, spontaneous reperfusion appearsto be beneficial for tissue survival. PET offers the uniquepossibility to assess tissue viability early after the ischaemicinjury where evaluation of wall motion fails to identify salvageablemyocardium.     

FDG双探头符合成像与X线断层图像同机融合在胸腹部肿瘤病变诊断中的价值

目的 :初步评价FDG双探头符合成像与X线断层图像同机融合在胸腹部肿瘤病变诊断中的价值。材料和方法 :回顾性分析 2 2例疑为胸腹部肿瘤或肿瘤术后复发而行18F -FDG双探头符合成像与X线断层联合扫描同机图像融合患者的资料。结果 :14例肿瘤或肿瘤术后复发的患者FDG显像 ,在 34个病灶中共检出 33个病灶 ( 97.1% )。融合影像可更加直观清晰地显示占位性病变或肿大淋巴结的代谢活性。其中 4例 ( 4 /14 )患者位于邻近膈肌上下及胸椎体、前列腺的 6个病灶 ( 6 /34)必须借助融合图像才能精确定位。结论 :FDG双探头符合成像与X线断层图像同机融合可明显提高符合显像定位诊断的准确性。