A mechanism for impaired fear recognition after amygdala damage

Ten years ago, we reported that SM, a patient with rare bilateral amygdala damage, showed an intriguing impairment in her ability to recognize fear from facial expressions. Since then, the importance of the amygdala in processing information about facial emotions has been borne out by a number of lesion and functional imaging studies. Yet the mechanism by which amygdala damage compromises fear recognition has not been identified. Returning to patient SM, we now show that her impairment stems from an inability to make normal use of information from the eye region of faces when judging emotions, a defect we trace to a lack of spontaneous fixations on the eyes during free viewing of faces. Although SM fails to look normally at the eye region in all facial expressions, her selective impairment in recognizing fear is explained by the fact that the eyes are the most important feature for identifying this emotion. Notably, SM's recognition of fearful faces became entirely normal when she was instructed explicitly to look at the eyes. This finding provides a mechanism to explain the amygdala's role in fear recognition, and points to new approaches for the possible rehabilitation of patients with defective emotion perception.     

Serum retinol binding protein 4 contributes to insulin resistance in obesity and type 2 diabetes

In obesity and type 2 diabetes, expression of the GLUT4 glucose transporter is decreased selectively in adipocytes. Adipose-specific Glut4 (also known as Slc2a4) knockout (adipose-Glut4(-/-)) mice show insulin resistance secondarily in muscle and liver. Here we show, using DNA arrays, that expression of retinol binding protein-4 (RBP4) is elevated in adipose tissue of adipose-Glut4(-/-) mice. We show that serum RBP4 levels are elevated in insulin-resistant mice and humans with obesity and type 2 diabetes. RBP4 levels are normalized by rosiglitazone, an insulin-sensitizing drug. Transgenic overexpression of human RBP4 or injection of recombinant RBP4 in normal mice causes insulin resistance. Conversely, genetic deletion of Rbp4 enhances insulin sensitivity. Fenretinide, a synthetic retinoid that increases urinary excretion of RBP4, normalizes serum RBP4 levels and improves insulin resistance and glucose intolerance in mice with obesity induced by a high-fat diet. Increasing serum RBP4 induces hepatic expression of the gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PEPCK) and impairs insulin signalling in muscle. Thus, RBP4 is an adipocyte-derived 'signal' that may contribute to the pathogenesis of type 2 diabetes. Lowering RBP4 could be a new strategy for treating type 2 diabetes.     

Planet-planet scattering in the upsilon Andromedae system

Doppler spectroscopy has detected 152 planets around nearby stars. A major puzzle is why many of their orbits are highly eccentric; all planets in our Solar System are on nearly circular orbits, as is expected if they formed by accretion processes in a protostellar disk. Several mechanisms have been proposed to generate large eccentricities after planet formation, but so far there has been little observational evidence to support any particular model. Here we report that the current orbital configuration of the three giant planets around upsilon Andromedae (upsilon And) probably results from a close dynamical interaction with another planet, now lost from the system. The planets started on nearly circular orbits, but chaotic evolution caused the outer planet (upsilon And d) to be perturbed suddenly into a higher-eccentricity orbit. The coupled evolution of the system then causes slow periodic variations in the eccentricity of the middle planet (upsilon And c). Indeed, we show that upsilon And c periodically returns to a very nearly circular state every 6,700 years.     

Genetisch bedingte Tumoren und der Gehalt an freien Aminosäuren beiNicotiana

Summary The amphidiploid hybrid ofNicotiana glauca ×N. langsdorffi, producing tumors spontaneously, contains essentially more of the following free amino acids than the inital species: cystine, histamine, oxyproline, alanine, kynurenine, tryptophane, and a non-identified ninhydrine positive substance. It is supposed that the abnormally high content of free amino acids is connected with the spontaneous formation of tumors.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Role of livestock and black-tailed jackrabbits in changing abundance of Kochia americana

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Historical accounts and matched photographs indicate sharp decline of once-abundant Kochia americana in eastern Great Basin vegetation since the early 1900s, most of the decline by the late 1950s. Exclosure data show further decline from 1957 to 1973, then some increase between 1970 and 1973 and 1976 and 1981. Utah sheep numbers, at maximum from 1925 to 1940 and declining steadily to the 1970s, may have induced the long-term changes. Black-tailed jackrabbits ( Lepus californicus ), could not have induced vegetation decline, but could have added to livestock pressure and abetted the trend. In 1972, rabbits near a cyclic high were indirectly estimated to completely utilize K. americana in Curlew Valley, northwestern Utah. In 1976–1977 at rabbit low, direct measurements show 4%–18% of plants browsed by late summer, about 30%–50% of herbage removed from browsed plants. The latter rose to 45%–82% by end of winter. Late-summer percent browsed may have risen slightly (11%–21%) in 1980–1981 at next rabbit high. Increase in K. americana density from 1973 to 1976, then a slight decrease from 1976 to 1980, suggests fluctuating K. americana abundance induced by rabbit browsing, superimposed on long-term K. americana decline and recovery.     

Thymus stimulation and cancer prophylaxis byViscum proteins

Zusammenfassung Die cancerostatischen Viscum-Proteine induzieren im Tierversuch mit geringsten Dosen eine Proliferation des Thymus und verhindern prophylaktisch das Angehen von Tumoren. Höhere Dosen zerstören dagegen den Immunapparat durch Überbeanspruchung und die Tumorhemmung bleibt aus.

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We are indebted to the Deutsche Forschungsgemeinschaft for financial support (M. St.) and for granting a Forschungsfreijahr (F. V.).     

多聚唾液酸转移酶ST8SiaⅡ的结构和功能域

ST8SiaⅡ(STX)和ST8SiaⅣ(PST)是两个来源于哺乳动物细胞的、具有高度同源性的多聚唾液酸酶,它们已经被克隆,基因序列也已被测定。这两个酶能催化神经细胞黏附分子(NCAM)的多聚唾液酸化。NCAM是多聚唾液酸(polySlA)的主要载体。在NCAM多聚唾液酸化过程中,STX和PST能将活化的胞苷-磷酸-乙酰神经氨酸(CMP-Neu5Ac)传送到NCAM糖蛋白受体的N-和O-型寡聚糖链上,从而合成α-2,8-多唾液酸聚糖(polySA)。近来我们使用Phyre 2软件构建了多聚唾液酸ST8SiaⅡ酶的三维结构模型,给出了该酶中多聚唾液酸转移酶结构域(PSTD)和多聚碱性氨基酸区域(PBR)两个功能域的结构特征,认为在这两个区域中有几个氨基酸残基在引起多聚唾液酸化过程中起到了关键作用。我们的研究结果为研究ST8SiaⅡ酶催化NCAM多聚唾液酸化的分子机制提供了新的结构信息,也为和该酶所联系的肿瘤细胞转移的抑制机制和抑制物/药物的研究和设计,提供更有价值的理论依据。     

The biocybernetic approach as a basis for planning our environment

In this paper, Professor Vester introduces the readers ofSystems Practice to his biocybernetic approach to systems planning, an approach that he has shown to be fruitful both in concrete applications and in many best-selling didactic publications, including children's books and games. Based on this approach he proposes a “cybernetic senstivity model,” a conceptual framework for ecologically sound systems design based on a biocybernetic redefinition of conventional techniques of systems modeling and simulation. The author explains the basic structure of the model and presents eight pertinent biocybernetic principles of good-systems practice. (Editor).     

Zur Indikation biochemischer Vorgänge durch kristallisierendes Kupferchlorid

Summary It is shown that differences in the asymmetry (optical impurities) of an added compound may influence considerably the crystallisation pattern of cupric chloride when crystallised under constant conditions on a glass plate. The high amplification of a purely formal difference in asymmetry calls for a specific information mechanism, one crystallographic possibility of which is discussed. This shows an approach to the problem of recognizing optical impurities in mixtures. The results are discussed in connection with the spontaneous racemisation in biochemical systems and may contribute to the understanding of the diagnostic biocrystallisation of copper chloride in cases of cancer