Response properties of human amygdala subregions : evidence based on functional MRI combined with probabilistic anatomical maps
Simon B. Eickhoff
- The human amygdala is thought to play a pivotal role in the processing of emotionally significant sensory information. The major subdivisions of the human amygdala—the laterobasal group (LB), the superficial group (SF), and the centromedial group (CM)—have been anatomically delineated, but the functional response properties of these amygdala subregions in humans are still unclear. We combined functional MRI with cyto-architectonically defined probabilistic maps to analyze the response characteristics of amygdala subregions in subjects presented with auditory stimuli. We found positive auditory stimulation-related signal changes predominantly in probabilistically defined LB, and negative responses predominantly in SF and CM. In the left amygdala, mean response magnitude in the core area of LB with 90–100% assignment probability was significantly larger than in the core areas of SF and CM. These differences were observed for pleasant and unpleasant stimuli. Our findings reveal that the probabilistically defined anatomical subregions of the human amygdala show distinctive fMRI response patterns. The stronger auditory responses in LB as compared with SF and CM may reflect a predominance of auditory inputs to human LB, similar to many animal species in which the majority of sensory, including auditory, afferents project to this subdivision of the amygdala. Our study indicates that the intrinsic functional differentiation of the human amygdala may be probed using fMRI combined with probabilistic anatomical maps.
Quantitative analysis of snoRNA association with pre-ribosomes and release of snR30 by Rok1 helicase
- In yeast, three small nucleolar RNAs (snoRNAs) are essential for the processing of pre-ribosomal RNA—U3, U14 and snR30—whereas 72 non-essential snoRNAs direct site-specific modification of pre-rRNA. We applied a quantitative screen for alterations in the pre-ribosome association to all 75 yeast snoRNAs in strains depleted of eight putative helicases implicated in 40S subunit synthesis. For the modification-guide snoRNAs, we found no clear evidence for the involvement of these helicases in the association or dissociation of pre-ribosomes. However, the DEAD box helicase Rok1 was required specifically for the release of snR30. Point mutations in motif I, but not in motif III, of the helicase domain of Rok1 impaired the release of snR30, but this was less marked than in strains depleted of Rok1, and resulted in a dominant-negative growth phenotype. Dissociation of U3 and U14 from pre-ribosomes is also dependent on helicases, suggesting that release of the essential snoRNAs might differ mechanistically from release of the modification-guide snoRNAs. Keywords: ribosome biogenesis; RNA helicase; snoRNA
AChBP-targeted alpha-conotoxin correlates distinct binding orientations with nAChR subtype selectivity
René van Elk
Paul F. Alewood
August B. Smit
Titia K. Sixma
Richard J. Lewis
- Neuronal nAChRs are a diverse family of pentameric ion channels with wide distribution throughout cells of the nervous and immune systems. However, the role of specific subtypes in normal and pathological states remains poorly understood due to the lack of selective probes. Here, we used a binding assay based on acetylcholine-binding protein (AChBP), a homolog of the nicotinic acetylcholine ligand-binding domain, to discover a novel alpha-conotoxin (alpha-TxIA) in the venom of Conus textile. alpha-TxIA bound with high affinity to AChBPs from different species and selectively targeted the alpha3beta2 nAChR subtype. A co-crystal structure of Ac-AChBP with the enhanced potency analog TxIA(A10L), revealed a 20° backbone tilt compared to other AChBP–conotoxin complexes. This reorientation was coordinated by a key salt bridge formed between Arg5 (TxIA) and Asp195 (Ac-AChBP). Mutagenesis studies, biochemical assays and electrophysiological recordings directly correlated the interactions observed in the co-crystal structure to binding affinity at AChBP and different nAChR subtypes. Together, these results establish a new pharmacophore for the design of novel subtype-selective ligands with therapeutic potential in nAChR-related diseases. Keywords: acetylcholine binding protein, conotoxin, cys-loop receptor, ion channel, nicotinic acetylcholine receptors
Indo-European vocabulary in Old Chinese : a new thesis on the emergence of Chinese language and civilization in the late Neolithic age
- This study is a much expanded version of the paper I read at the XXXII International Congress for Asian and North African Studies on August 28, 1986 in Hamburg (Germany). Contents 1. Recent developments in the field of historical linguistics 2. Monosyllabic structure of Chinese words and Indo-European stems 3. Tonal accents of Middle Chinese 4. Preliminaries on the comparison of consonants and vowels 5. Some IE stems corresponding to Chinese words of entering tone 6. Middle Chinese tones and final consonants of IE stems 7. Some IE stems corresponding to Chinese words of rising tone 8. Some IE stems corresponding to Chinese words of vanishing tone 9. Some IE stems corresponding to Chinese words of level tone 10. Reconstruction of Middle Chinese vocalism according to Yün-ching 11. Old Chinese vocalism 12. Vocalic correspondences between Chinese and IE 13. Initials of Old Chinese 14. Initial consonant clusters in Old Chinese as seen from IE-stems 15. Proximity of Chinese to Germanic 16. Relation of Old Chinese to neighboring languages 17. Emergence of Chinese Empire and language in the middle of the third millennium B.C. Appendix * Abbrevations * Bibliography * Rhyme Tables of Early Middle Chinese (600) * Rhyme Tables of Early Mandarin (1300) * Word Index o English o Pinyin In 1786, just over two hundred years ago, comparative historical linguistics was born, when Sir William Jones (1746-1794) discovered the relationship between Old-Indian Sanskrit, Greek, and Latin. Since then, the emerging Indo-European philology has thrown much light on the early history of mankind in Eurasia. During the past two hundred years, many suggestions were also made in regard to relationships of Indo-European to other languages such as Semitic, Altaic, Austronesian, Korean etc., but Indo-Europeanists commonly rejected such attempts for want of convincing evidence. As to Chinese, Joseph Edkins was the first to advance the thesis of its proximity to Indo-European. In his work China's Place in Philology. An Attempt to show that the Language of Europe and Asia have a Common Origin (1871) he presented a number of Chinese words similar to those of Indo-European. In his time, Edkins' thesis seemed bold and extravagant. But today, more than a hundred years later, we are in a much better position to carry out a comprehensive and well-founded comparative study. Since the end of the nineteenth century, many Sinologists have been engaged in reconstruction of the mediaeval and archaic readings of Chinese characters. Among them, Karlgren (1889-1978) was the most successful, and in 1940 he published a comprehensive phonological and etymological dictionary entitled Grammata Serica. In the meantime, the Indo-Europeanists Alois Walde (1869-1924) and Julius Pokorny (1887-1970) were devoting themselves to the compilation of a useful etymological dictionary. The result was the Indogermanisches Etymologisches Wörterbuch by Pokorny (1959) which provides a solid basis for our lexical comparisons. Soon thereafter, some Sinologists made use of the two dictionaries by Karlgren and Pokorny to compare Chinese and Indo-European words. In 1967, an unaffiliated German scholar, Jan Ulenbrook, published an article "Einige Übereinstirnrnungen zwischen dem Chinesischen und dem Indogermanischen", in which he claimed that 57 words are related. Shortly afterwards, Tor Ulving of the University of Goteborg, Sweden, wrote a review of this article framing the title as a question: "Indo-European elements in Chinese?" While working on his thesis on word families in Chinese, Ulving compiled for his own use two dictionaries: "Archaic Chinese - English" and "English - Archaic Chinese", and discovered thereby 238 Chinese words similar to Indo-European roots. In spite of this considerable number of word equivalents, however, Mr. Ulving became discouraged and, as he told me in his letter of April, 1986, has given up his researches in this field. The skepticism, common among Indo-Europeanists in regard to comparative studies with other languages, is largely based on the dogmatic opinion that only morphology is relevant but not vocabulary. Since the typology of Chinese seems to preclude a cognate relation to Indo-European, they are inclined to discard any lexical correspondences as merely accidental or onomatopoetic. Besides, prehistorical contacts and mixtures between these languages seem not conceivable, as the Indo-Europeans are supposed to have originated in Northern Europe or at best in the Central Asian steppe, thousands of miles away from East Asia. Hence, any research into a relationship between Old Chinese and Indo-European languages would be but futile from the outset. Yet there are also opposing views among Indo-Europeanists. Investigations into Germanic languages and the oldest Indo-European language, Hittite, led some of them to a critical revision of the prevailing conception about a Proto-Indo-European. Hermann Hirt (1934) for instance states: "Inflexion of Indo-European languages is due to a relatively late development, and its correct comprehension can be achieved only by proceeding from the time of non-inflexion." And Carl Karstien (1936) holds the opinion that "Chinese corresponds most ideally to the hypothetic prototype of Indo-European." Regarding vocabulary, there are striking similarities in the monosyllabic structure of the basic words. In modern German and English, all the words of everyday speech are monosyllabic and their stereotypical structure is: initial consonant(s) + vowel(s) + final consonant(s). The same word structure is valid for Chinese as well. It is fundamentally different from the disyllabic structure of Altaic words and from the triconsonantal-disyllabic structure of Semitic words. Characteristic of the monosyllabic word structure is, besides, the complexity of the syllable nucleus, which consists of different vowels and vowel clusters in contrast to the monophthongal vocalism of polysyllabic words. Another objection raised to comparisons between Chinese and Indo-European is the existence of tonal accents in Chinese. Since most modern Indo-European languages have only expiratory accents, Chinese is considered to be a highly exotic language. Yet, even in Chinese, the use of tonal accents as a means of lexical differentiation is a result of comparatively recent development in the long history of Chinese language, the earliest monuments of which date back to 1300 B.C. (cf. Chang 1970, p.21). Unknown to Old Chinese, the existence of tonal accents was for the first time mentioned in the 5th century by Shen Yüeh (441-513). In Middle Chinese (Mch.) there were four tone categories: A P'ing-sheng 平 a level tone (which developed into Mandarin tone 1 or 2). B Shang-sheng 上 a rising tone (Mandarin tone 3). C Ch'u-sheng 去 a vanishing, i.e. falling tone (Mandarin tone 4). D Ju-sheng 入 an entering tone with a staccato effect, the word being abruptly stopped by a final consonant -p, -t, -k. (In Early Mandarin the words of this tone lost their final consonant and were distributed among the tones 2, 3 and 4, respectively according to the phonation of initials). In Middle Chinese, words of the entering tone were the only group which still preserved the final stops and therefore a close syllabic structure. So they are most appropriate for convincing comparisons with monosyllabic Indo-European word stems. The final stops -p, -t, -k of the entering tone are nowadays still extant in daily speech of several dialects in South China as well as in Chinese borrowings in Japanese, Vietnamese and Korean. As a speaker of a Taiwan dialect of Minnan origin, I could immediately identify some Indo-European stems with corresponding Chinese words. Besides, the command of Japanese and German was also a great help for this study. In the following lists I have chosen a number of Indo-European stems which are phonetically and semantically equivalent to Chinese words. Correspondences in initial and final consonants refer to the points of articulation, thus we have equations: IE labials = Old Chinese labials, IE dentals = dentals, IE l, r = dentals (cf. p. 31); Ø, i (final and medial) IE velars = velars and laryngeals, and occasionally (the so-called "satem"-forms) IE velars = dental sibilants and affricates. Regarding the manner of articulation, there are no regular correspondences between Indo-European and Chinese consonants like Grimm's law which is valid among Indo-European dialects to a certain extent. But this is not astonishing, since in Old Chinese the alternation of initials in voicing was a conventional means of creating new words from one basic form. The rules of vocalic correpondences among Indo-European dialects are quite complex. Vowels permanently change their qualities from one language to another, and from time to time within one language also, as is well known from the history of English pronunciations. Generally, the vocalism of Old Greek is taken as the standard for Proto-Indo-European. Old Chinese vowels corresponds nearly (cf. p. 30), but the details about the reconstruction of Middle and Old Chinese vocalism will be treated later (pp. 26-30). For the moment, it is necessary to notice in advance that the stem of ablauting Germanic verbs is the form of preterite or noun, rather than that of infinitive as assumed hitherto. Therefore, in some cases I must slightly modify the basic vowel of verbal stems given in Pokorny, in order to get better basis for comparison. As Old Chinese verbs were non-flexional, they might probably have preserved the original vowel the best.
Covalently bound substrate at the regulatory site triggers allosteric enzyme activation
Manfred S. Weiss
- The mechanism by which the enzyme pyruvate decarboxylase from yeast is activated allosterically has been elucidated. A total of seven three-dimensional structures of the enzyme, of enzyme variants or of enzyme complexes from two yeast species (three of them reported here for the first time) provide detailed atomic resolution snapshots along the activation coordinate. The prime event is the covalent binding of the substrate pyruvate to the side chain of cysteine 221, thus forming a thiohemiketal. This reaction causes the shift of a neighbouring amino acid, which eventually leads to the rigidification of two otherwise flexible loops, where one of the loops provides two histidine residues necessary to complete the enzymatically competent active site architecture. The structural data are complemented and supported by kinetic investigations and binding studies and provide a consistent picture of the structural changes, which occur upon enzyme activation.
[11C]-L-Methionine positron emission tomography in the management of children and young adults with brain tumors
Lutz Walter Kracht
Johannes Christian Klein
Andreas H. Jacobs
- Only a few Methyl-[11C]-l-methionine (MET) positron emission tomography (PET) studies have focused on children and young adults with brain neoplasm. Due to radiation exposure, long scan acquisition time, and the need for sedation in young children MET-PET studies should be restricted to this group of patients when a decision for further therapy is not possible from routine diagnostic procedures alone, e.g., structural imaging. We investigated the diagnostic accuracy of MET-PET for the differentiation between tumorous and non-tumorous lesions in this group of patients. Forty eight MET-PET scans from 39 patients aged from 2 to 21 years (mean 15 ± 5.0 years) were analyzed. The MET tumor-uptake relative to a corresponding control region was calculated. A receiver operating characteristic (ROC) was performed to determine the MET-uptake value that best distinguishes tumorous from non-tumorous brain lesions. A differentiation between tumorous (n = 39) and non-tumorous brain lesions (n = 9) was possible at a threshold of 1.48 of relative MET-uptake with a sensitivity of 83% and a specificity of 92%, respectively. A differentiation between high grade malignant lesions (mean MET-uptake = 2.00 ± 0.46) and low grade tumors (mean MET-uptake = 1.84 ± 0.31) was not possible. There was a significant difference in MET-uptake between the histologically homogeneous subgroups of astrocytoma WHO grade II and anaplastic astrocytoma WHO grade III (P = 0.02). MET-PET might be a useful tool to differentiate tumorous from non-tumorous lesions in children and young adults when a decision for further therapy is difficult or impossible from routine structural imaging procedures alone. Keywords Brain tumor - Children - PET - Methionine - Molecular imaging
Nuclear translocation and signalling of L1-CAM in human carcinoma cells requires ADAM10 and presenilin/gamma-secretase activity
- L1-CAM (L1 cell-adhesion molecule), or more simply L1, plays an important role in the progression of human carcinoma. Overexpression promotes tumour-cell invasion and motility, growth in nude mice and tumour metastasis. It is feasible that L1-dependent signalling contributes to these effects. However, little is known about its mechanism in tumour cells. We reported previously that L1 is cleaved by ADAM (a disintegrin and metalloprotease) and that the cytoplasmic part is essential for L1 function. Here we analysed more closely the role of proteolytic cleavage in L1-mediated nuclear signalling. Using OVMz carcinoma cells and L1-transfected cells as a model, we found that ADAM10-mediated cleavage of L1 proceeds in lipid raft and non-raft domains. The cleavage product, L1-32, is further processed by PS (presenilin)/gamma-secretase to release L1-ICD, an L1 intracellular domain of 28 kDa. Overexpression of dominantnegative PS1 or use of a specific gamma-secretase inhibitor leads to an accumulation of L1-32. Fluorescence and biochemical analysis revealed a nuclear localization for L1-ICD. Moreover, inhibition of ADAM10 and/or gamma-secretase blocks nuclear translocation of L1-ICD and L1-dependent gene regulation. Overexpression of recombinant L1-ICD mediates gene regulation in a similar manner to full-length L1. Our results establish for the first time that regulated proteolytic processing by ADAM10 and PS/gamma-secretase is essential for the nuclear signalling of L1 in human carcinoma cell lines. Key words: a disintegrin and metalloprotease 10 (ADAM10), L1 cell-adhesion molecule (L1-CAM), nuclear translocation, presenilin (PS)/gamma-secretase activity, raft, signalling.
From heterogeneity to harmonization? : Recent trends in European health policy = Da heterogeneidade à harmonização?
- In the European Union (EU), health policy and the institutional reform of health systems have been treated primarily as national affairs, and health care systems within the EU thus differ considerably. However, the health policy field is undergoing a dynamic process of Europeanization. This process is stimulated by the orientation towards a more competitive economy, recently inaugurated and known as the Lisbon Strategy, while the regulatory requirements of the European Economic and Monetary Union are stimulating the Europeanization of health policy. In addition, the so-called open method of coordination, representing a new mode of regulation within the European multi-level system, is applied increasingly to the health policy area. Diverse trends are thus emerging. While the Lisbon Strategy goes along with a strategic upgrading of health policy more generally, health policy is increasingly used to strengthen economic competitiveness. Pressure on Member States is expected to increase to contain costs and promote market-based health care provision. European Union; Health Policy; Health Systems
Genetic engineering of baker’s and wine yeasts using formaldehyde hyperresistance-mediating plasmids
- Yeast multi-copy vectors carrying the for maldehyde-resistance marker gene SFA have proved to be a valuable tool for research on industrially used strains of Saccharomyces cerevisiae. The genetics of these strains is often poorly understood, and for various reasons it is not possible to simply subject these strains to protocols of genetic engineering that have been established for laboratory strains of S. cerevisiae. We tested our vectors and protocols using 10 randomly picked baker’s and wine yeasts all of which could be transformed by a simple protocol with vectors conferring hyperresistance to formaldehyde. The application of formaldehyde as a selecting agent also offers the advantage of its biodegradation to CO2 during fermentation, i.e., the selecting agent will be consumed and therefore its removal during down-stream processing is not necessary. Thus, this vector provides an expression system which is simple to apply and inexpensive to use. Key words: · Yeast · Transformation · Hyperresistance to formaldehyde
Identification of biology-based breast cancer types with distinct predictive and prognostic features : role of steroid hormone and HER2 receptor expression in patients treated with neoadjuvant anthracycline/taxane-based chemotherapy
Berit Maria Müller
Jens Uwe Blohmer
Andreas Du Bois
Gunter von Minckwitz
- Introduction: Reliable predictive and prognostic markers for routine diagnostic purposes are needed for breast cancer patients treated with neoadjuvant chemotherapy. We evaluated protein biomarkers in a cohort of 116 participants of the GeparDuo study on anthracycline/taxane-based neoadjuvant chemotherapy for operable breast cancer to test for associations with pathological complete response (pCR) and disease-free survival (DFS). Particularly, we evaluated if interactions between hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) expression might lead to a different clinical behavior of HR+/HER2+ coexpressing and HR+/HER2- tumors and whether subgroups of triple negative tumors might be identified by the help of Ki67 labeling index, cytokeratin 5/6 (CK5/6), as well as cyclooxygenase-2 (COX-2), and Y-box binding protein 1 (YB-1) expression. Methods: Expression analysis was performed using immunohistochemistry and silver-enhanced in situ hybridization on tissue microarrays (TMAs) of pretherapeutic core biopsies. Results: pCR rates were significantly different between the biology-based tumor types (P = 0.044) with HR+/HER2+ and HR-/HER2- tumors having higher pCR rates than HR+/HER2-tumors. Ki67 labeling index, confirmed as significant predictor of pCR in the whole cohort (P = 0.001), identified HR-/HER- (triple negative) carcinomas with a higher chance for a pCR (P = 0.006). Biology-based tumor type (P = 0.046 for HR+/HER2+vs. HR+/HER2-), Ki67 labeling index (P = 0.028), and treatment arm (P = 0.036) were independent predictors of pCR in a multivariate model. DFS was different in the biology-based tumor types (P < 0.0001) with HR+/HER2- and HR+/HER2+ tumors having the best prognosis and HR-/HER2+ tumors showing the worst outcome. Biology-based tumor type was an independent prognostic factor for DFS in multivariate analysis (P < 0.001). Conclusions: Our data demonstrate that a biology-based breast cancer classification using estrogen receptor (ER), progesterone receptor (PgR), and HER2 bears independent predictive and prognostic potential. The HR+/HER2+ coexpressing carcinomas emerged as a group of tumors with a good response rate to neoadjuvant chemotherapy and a favorable prognosis. HR+/HER2- tumors had a good prognosis irrespective of a pCR, whereas patients with HR-/HER- and HR-/HER+ tumors, especially if they had not achieved a pCR, had an unfavorable prognosis and are in need of additional treatment options. Trial registration ClinicalTrials.gov identifier: NCT00793377