Abnormal face identity coding in the middle fusiform gyrus of two brain-damaged prosopagnosic patients

We report a functional magnetic resonance imaging (fMRI) adaptation study of two well-described patients, DF and PS, who present face identity recognition impairments (prosopagnosia) following brain-damage. Comparing faces to non-face objects elicited activation in all visual areas of the cortical face processing network that were spared subsequent to brain damage. The common brain lesion in the two patients was in the right inferior occipital cortex, in the territory of the right “occipital face area” (‘OFA’), which strengthens the critical role of this region in processing faces. Despite the lesion to the right ‘OFA’, there was normal range of sensitivity to faces in the right “fusiform face area” (‘FFA’) in both patients, supporting a non-hierarchical model of face processing at the cortical level. At the same time, however, sensitivity to individual face representations, as indicated by release from adaptation to identity, was abnormal in the right ‘FFA’ of both patients. This suggests that the right ‘OFA’ is necessary to individualize faces, perhaps through reentrant interactions with other cortical face sensitive areas. The lateral occipital area (LO) is damaged bilaterally in patient DF, who also shows visual object agnosia. However, in patient PS, in whom LO was spared, sensitivity to individual representations of non-face objects was still found in this region, as in the normal brain, consistent with her preserved object recognition abilities. Taken together, these observations, which fruitfully combine functional imaging and neuropsychology, place strong constraints on the possible functional organization of the cortical areas mediating face processing in the human brain.     

Free fatty acids have more potent effects on gastric emptying, gut hormones, and appetite than triacylglycerides

BACKGROUND & AIMS: The effects of fat on gastric emptying (GE), gut hormones, and energy intake are dependent on digestion to free fatty acids (FFAs). In animals, small intestinal oleic acid inhibits energy intake more potently than the triacylglyceride (TG) triolein, but there is limited information about the comparative effects of FFA and TG in human beings. We compared the effects of FFA and TG on GE, gut hormone secretion, appetite, and energy intake in healthy males. METHODS: Nine men (age, 23 +/- 2 y; body mass index, 22 +/- 1 kg/m(2)) were studied on 3 occasions to evaluate the effects of (1) 40 g oleic acid (FFA, 1830 kJ), (2) 40 g macadamia oil (TG, 1856 kJ; both 600-mL oil-in-water emulsions stabilized with 4% milk protein and labeled with 15 MBq (123)I), or (3) 600 mL 4% milk protein (control, 352 kJ), administered intragastrically, on GE, plasma cholecystokinin (CCK) and peptide-YY (PYY) levels, appetite perceptions, and subsequent energy intake. RESULTS: GE of FFA was much slower than that of TG (P < .05), with greater retention of FFA, than TG, in the proximal stomach (P < .001). Hunger was less (P < .05), and fullness was greater (P < .05), after FFA when compared with control and TG. Increases in plasma CCK and PYY levels were greater after FFA than TG or control (P < .05). Energy intake tended to be less after FFA compared with TG (control, 4754 +/- 610 kJ; TG, 5463 +/- 662 kJ; FFA, 4199 +/- 410 kJ). CONCLUSIONS: FFAs empty from the stomach more slowly, but stimulate CCK and PYY and suppress appetite more potently than TG in healthy human beings.     

Antihyperglycemic activity of Selaginella tamariscina (Beauv.) Spring

Aim of the study

The present study was designed to investigate the effects of the EtOH and H₂O extracts of Selaginella tamariscina (Beauv.) Spring on hyperglycemia in diabetic rats and HepG2 cells, and to confirm the active fractions of EtOH extract in HepG2 cells.

Materials and methods

HepG2 cells and type II diabetic rats induced by low-dose streptozotocin (STZ) and high-fat diet (HFD) were used to evaluate the hypoglycemic effect of EtOH and H₂O extracts of Selaginella tamariscina. HepG2 cells were used to evaluate the promotive effect of different fractions of EtOH extract obtained from a polyamide column on glucose utilization.

Results

The results in HepG2 cells indicated that the EtOH extract had a better hypoglycemic effect than the H₂O extract. The results in diabetic rats indicated that both EtOH extract and H₂O extract were able to ameliorate the fasting blood glucose (FBG) level and improve oral glucose tolerance (OGTT). Total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-c), free fatty acids (FFA), tumor necrosis factor-α (TNF-α), alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and malondialdehyde (MDA) levels in serum were lowered. High density lipoprotein (HDL-c), insulin and superoxide dismutase (SOD) levels in serum were elevated as well as the hepatic glycogen content in diabetic rats. Compared with H₂O extract, the effects of EtOH extract were more marked. The 80% ethanol fraction exhibited a stronger hypoglycemic effect than the aqueous and 50% ethanol fractions, but the 95% ethanol fraction did not show any appreciable effects in HepG2 cells.

Conclusions

The results suggested that the EtOH extract had a better hypoglycemic effect than the H₂O extract; the 80% ethanol fraction from polyamide column had a strong hypoglycemic activity in HepG2 cells.     

老龄大鼠肝脏和骨骼肌胰岛素受体底物-1及磷酸化蛋白激酶B的表达

目的 探讨老龄对胰岛素受体底物-1(IRS-1)/磷脂酰肌醇3激酶(PI3K)/蛋白激酶B (PKB, p-Akt)在肝脏和骨骼肌中表达的影响,为老年糖尿病早期干预方法提供实验依据. 方法 3种不同月龄SD大鼠(6、12、20～24月龄),腹腔麻醉后抽心血查血糖、血脂、游离脂肪酸(FFA);分离肝脏、骨骼肌,免疫组化观察IRS-1与p-Akt在不同月龄大鼠肝脏和骨骼肌中的表达. 结果 20～24月龄鼠血浆中FFA水平高于6月龄大鼠[(419.94±93.93) vs (256.22±73.93 ) mmol/L, P<0.05];但空腹血糖及血脂水平与其它月龄大鼠相当;在肝脏或骨骼肌均未发现IRS-1表达水平的显著变化(P>0.05);p-Akt在肝细胞中的表达减少,与6月龄和12月龄组相比差异有统计学意义(P<0.05);而在骨骼肌细胞中,3组动物p-Akt表达无明显差异. 结论 FFA水平增高是自然衰老大鼠胰岛素抵抗的显著特征,与此相关的PI3K/Akt信号通路障碍早于血糖异常出现;Akt 的磷酸化障碍可能是早期干预的靶点.Akt 的磷酸化障碍主要在肝细胞中发现,肝脏可能是衰老相关胰岛素信号通路异常的主要部位.     

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.     

Alteration of Connexin43 expression in a rat model of obesity-related glomerulopathy

It is accepted that alteration of connexin43 (Cx43) expression in glomeruli is a common pathological response in several forms of kidney diseases. To date, however the change of the Cx43 expression in obesity-related glomerulopathy (ORG) has not been reported. In this study, the alteration of Cx43 expression in the glomeruli of rat with ORG was defined. Five-week-old rats were fed with high-fat diet for 18 weeks to establish the ORG model, then the histological change of glomeruli, the foot process effacement of podocyte, the markers for podocyte injury (nephrin,podocin and WT1) and Cx43 expression in glomeruli were examined respectively. The results demonstrated metabolic disorder, hyperinsulinemia, systemic inflammation and microalbuminuria in ORG rats. There was significant hypertrophy, glomerular expansion and inflammatory cell infiltration in the kidney of ORG rats compared to the control group. Significant foot process effacement of the podocyte in the glomeruli, nephrin loss and density reduction were shown in the ORG rats, and Cx43 expression was significant upregulated in glomeruli of ORG rats compared to the control group. The results indicate the correlation of overexpressed Cx43 with the obesity related renal inflammation and suggest that Cx43 might be a potential target in the development of obesity related glomerulopathy.     

Heterogeneity of human serum high-density lipoprotein (HDL 2 )

A technique is described for the detection of free fatty acids, triglycerides, wax esters and cholesterol esters on thin-layer Chromatographic plates. The fatty acids present in each fraction can be recovered from the plates after detection and quantitatively measured by gas-liquid chiomatography. This procedure has been sucessfully applied to the analysis of skin surface lipids.     

超氧化物歧化酶及游离脂肪酸检测在胰岛素抵抗疾病中的应用

目的 探讨超氧化物歧化酶(SOD)及游离脂肪酸(FFA)检测在胰岛素抵抗疾病中的应用价值.方法 选择300例2型糖尿病(DM2)患者,其中150例合并非酒精性脂肪肝(NAFLD),空腹采血检测超氧化物歧化酶(SOD)、游离脂肪酸(FFA)、胰岛素(INS)、葡萄糖(FPG)、脂类等实验室指标,同时做肝脏瞬时弹性检查(FibroScan)和受控衰减参数(CAP);选择150例体检健康者为对照组,做相同检测.结果 糖尿病组和合并NAFLD组检测结果进行对比,各项指标的差异均具有统计学意义(P＜0.05),糖尿病组、合并NAFLD组与对照组的检测结果进行对比,各项指标的差异均具有统计学意义(P＜0.05).结论 超氧化物歧化酶及游离脂肪酸检测在胰岛素抵抗疾病中有重要的应用价值.     

OCT在Vogt-小柳原田综合征临床诊疗中的作用

目的 探讨频域相干光断层扫描(Optical Coherence Tonography,OCT)在Vogt-小柳原田综合征(VKH)临床诊疗过程中的作用.方法 对14例28只眼VKH患者早期行OCT检查,并行荧光素眼底血管造影(FFA).全部病例均应用甲强龙冲击3天后糖皮质激素口服治疗,在用药前、口服药前及口服强的松1周、1个后月均行OCT检查.结果 14例28只眼VKH患者早期OCT检查表现为视网膜神经上皮层及色素上皮层渗出性脱离、隆起呈泡状或多囊状.神经上皮最大脱离高度4058μm,最小脱离高度156 μm,平均(2869±138.65)μm,最大脱离直径超过6 mm扫描范围,最小直径1348 μm,色素上皮单发或多发脱离,应用甲强龙冲击3天后神经上皮脱离快速消退,神经上皮最大脱离高度2058 μm,最小脱离高度49μm,平均(1345±115.85) μm,最大脱离直径2568 μm,最小直径563μm,平均(1078±98.43)μm,与治疗前对比差异有统计学意义(P＜0.05).用药7～10天后 神经上皮及色素上皮脱离均消退,视乳头水肿明显减轻,所有患者均恢复至发病前视力,1个月后黄斑区神经上皮及色素上皮恢复正常,合并视乳头水肿者水肿均消退,视力稳定无下降.结论 OCT在VKH临床早期诊断、诊疗效果的评价以及与患者沟通方面均具有重要临床意义.     

Chitooligosaccharide ameliorates diet-induced obesity in mice and affects adipose gene expression involved in adipogenesis and inflammation

Chitooligosaccharide (CO) has been reported to have potential antiobestic effects in a few studies, but the antiobesity properties of CO and its related mechanisms in models of dietary obesity remain unclear. We investigated the effect of CO on body weight gain, size of adipocytes, adipokines, and lipid profiles in high-fat (HF) diet-induced obese mice and on the gene expression in adipose tissue using a complementary DNA microarray approach to test the hypothesis that CO supplementation would alleviate HF diet-induced obesity by the alteration of adipose tissue-specific gene expression. Male C57BL/6N mice were fed a normal diet (control), HF diet, or CO-supplemented HF diet (1% or 3%) for 5 months. Compared with the HF diet mice, mice fed the 3% CO-supplemented diet gained 15% less weight but did not display any change in food and energy intake. Chitooligosaccharide supplementation markedly improved serum and hepatic lipid profiles. Histologic examination showed that epididymal adipocyte size was smaller in mice fed the HF + 3% CO. Microarray analysis showed that dietary CO supplementation modulated adipogenesis-related genes such as matrix metallopeptidases 3, 12, 13, and 14; tissue inhibitor of metalloproteinase 1; and cathepsin k in the adipose tissues. Twenty-five percent of the CO-responsive genes identified are involved in immune responses including the inflammatory response and cytokine production. These results suggest that CO supplementation may help ameliorate HF diet-induced weight gain and improve serum and liver lipid profile abnormalities, which are associated, at least in part, with altered adipose tissue gene expression involved in adipogenesis and inflammation.