Dystrophin (Xp21), a New Phenotype Marker of Cultured Rat Aortic Myocytes

Dystropbin is a low-abundance cytoskeletal protein involved in the maintenance of membrane integrity in striated muscle. Very little is known about its role in smooth muscle. Utrophin (a dystropbin-related protein) is an ubiquitous protein whose role is still unclear. Changes in the expression of both proteins (if any) during phenotypic modulation of smooth muscle have not yet been reported. In contrast, modulated expression of heavy-molecular-weight caldesmon (h-CaD), a well-known specific regulatory protein of the contractile apparatus in smooth muscle, is well documented, along with its nonmuscle isoform, low-molecular-weight caldesmon (l-CaD), and other cytoskeletal proteins. We investigated three properties of cultured rat aortic smooth muscle cells: morphology, contractile ability, and expression of dystrophin, utrophin, h-CaD, and l-CaD. Cells were grown either in serum substitute supplemented medium (U-medium), where they reexpressed contractility, or in fetal calf serum-supplemented medium (F-medium), where they did not. It was found that only cultures grown in U-medium continued expressing dystrophin, even during the proliferation phase, contrary to cells grown in F-medium. However, when F-medium was changed for U-medium the cells recovered their contractility and reexpressed dystrophin. Expression of utrophin, h-CaD, and l-CaD was similar in both culture types. Dystrophin was demonstrated to be a true phenotype marker of cultured rat aortic smooth muscle cells, particularly with respect to their actual contractility.     

Metacercarial dispersion and intracellular parasitism in a strigeid trematode

Combes C. and Nassi H. 1977. Metacercarial dispersion and intracellular parasitism in a strigeid trematode. International Journal for Parasitology7: 501–503. The life cycle of Apatemon graciliformis Szidat, 1928 (Trematoda, Strigeidae), a parasite of Biorrphalaria glabrata in Guadeloupe, involves a novel mode of transmission, experimentally demonstrated, between the second intermediate host and the definitive host. The furcocercariae penetrate gravid females of the ovoviviparous fish, Poecilia reticulata, and develop into metacercariae in vitelline vesicles of the embryos where they encyst a short time before parturition. The young guppies are born infected with 1–3 metacercariae. It is considered that young infected fish are more prone to predation by the definitive host, thereby increasing the probability of the cycle being completed. Domestic ducks have been experimentally infected with these metacercariae. If cercariae penetrate non-gravid P. reticulata, they enter the oocytes; this represents a phase of intracellular parasitism.     

One-step synthesis of Gly-Gly-PheNH2 from N-unprotected amino acid derivatives by papain in one-phase liquid media

Summary Papain was able to catalyze the one-step synthesis of Gly-Gly-PheNH₂, from N-unprotected amino acid derivatives. Maximum synthetic activity was obtained for a pH value of 6.5 and for a ]PheNH₂]/[Gly-GlyOEt] ratio of 6. The presence of an organic cosolvent, such as ethylene glycol, influenced the synthetic activity. Synthetic yield was higher than 65% for a 12.5 M cosolvent concentration.     

BAC-end sequences analysis provides first insights into coffee (Coffea canephora P.) genome composition and evolution

Coffee is one of the world’s most important agricultural commodities. Coffee belongs to the Rubiaceae family in the euasterid I clade of dicotyledonous plants, to which the Solanaceae family also belongs. Two bacterial artificial chromosome (BAC) libraries of a homozygous doubled haploid plant of Coffea canephora were constructed using two enzymes, HindIII and BstYI. A total of 134,827 high quality BAC-end sequences (BESs) were generated from the 73,728 clones of the two libraries, and 131,412 BESs were conserved for further analysis after elimination of chloroplast and mitochondrial sequences. This corresponded to almost 13 % of the estimated size of the C. canephora genome. 6.7 % of BESs contained simple sequence repeats, the most abundant (47.8 %) being mononucleotide motifs. These sequences allow the development of numerous useful marker sites. Potential transposable elements (TEs) represented 11.9 % of the full length BESs. A difference was observed between the BstYI and HindIII libraries (14.9 vs. 8.8 %). Analysis of BESs against known coding sequences of TEs indicated that 11.9 % of the genome corresponded to known repeat sequences, like for other flowering plants. The number of genes in the coffee genome was estimated at 41,973 which is probably overestimated. Comparative genome mapping revealed that microsynteny was higher between coffee and grapevine than between coffee and tomato or Arabidopsis. BESs constitute valuable resources for the first genome wide survey of coffee and provide new insights into the composition and evolution of the coffee genome.     

Cities through the Prism of People’s Spending Behavior

Scientific studies of society increasingly rely on digital traces produced by various aspects of human activity. In this paper, we exploit a relatively unexplored source of data–anonymized records of bank card transactions collected in Spain by a big European bank, and propose a new classification scheme of cities based on the economic behavior of their residents. First, we study how individual spending behavior is qualitatively and quantitatively affected by various factors such as customer’s age, gender, and size of his/her home city. We show that, similar to other socioeconomic urban quantities, individual spending activity exhibits a statistically significant superlinear scaling with city size. With respect to the general trends, we quantify the distinctive signature of each city in terms of residents’ spending behavior, independently from the effects of scale and demographic heterogeneity. Based on the comparison of city signatures, we build a novel classification of cities across Spain in three categories. That classification exhibits a substantial stability over different city definitions and connects with a meaningful socioeconomic interpretation. Furthermore, it corresponds with the ability of cities to attract foreign visitors, which is a particularly remarkable finding given that the classification was based exclusively on the behavioral patterns of city residents. This highlights the far-reaching applicability of the presented classification approach and its ability to discover patterns that go beyond the quantities directly involved in it.     

Giant aneurysm of an aortocoronary venous bypass graft compressing the right ventricle

A 69-year-old man with a history of coronary artery bypass grafting and a recent inferoposterior myocardial infarction presented to the hospital for diagnostic coronary angiography. Physical examination, laboratory analyses, coronary angiography, echocardiography, and CT scan were performed. A giant aneurysm of the aortocoronary venous bypass graft, associated with compression of the right side of the heart, was revealed. After surgical resection and replacement of the venous graft the patient died due to right ventricular failure. (Neth Heart J 2007;15:252-4.)     

Mating behaviour in Schistosomes: are paired worms always faithful?

Previously assumed to be monogamous, the mating system of schistosomes has been the subject of some debate since recent findings have shown that change of mate can occur among these parasites. Here, Louis-Albert Tchuem Tchuenté, Vaughan R. Southgate, Claude Combes and Joseph Jourdane review progress made in the understanding of the mating behaviour of schistosomes, and highlight the importance of mating systems in the dynamics of natural transmission of schistosomiasis.     

Helminth eggs in animal coprolites from a Middle Pleistocene site in Europe

This paper reports on the discovery of dicrocoelid eggs in a coprolite collected in an archeological layer dated earlier than 550,000 yr BP (before present) from the Caune de l'Arago cave (Tautavel, Pyrénées-Orientales, France). It is the first trematode egg finding in an isolated coprolite from the Middle Pleistocene context.     

Construction and characterisation of a BAC library for genome analysis of the allotetraploid coffee species (<Emphasis Type="Italic">Coffea arabica</Emphasis> L.)

In order to promote genome research on coffee trees, one of the most important tropical crops, a bacterial artificial chromosome (BAC) library of the coffee allotetraploid species, Coffea arabica, was constructed. The variety IAPAR 59, which is widely distributed in Latin America and exhibits a fair level of resistance to several pathogens, was chosen. High-efficiency BAC cloning of the high molecular weight genomic DNA partially digested by HindIII was achieved. In total, the library contains 88,813 clones with an average insert size of 130 kb, and represents approximately eight C. arabica dihaploid genome equivalents. One original feature of this library is that it can be divided into four sublibraries with mean insert sizes of 96, 130, 183 and 210 kb. Characterisation of the library showed that less than 4.5% of the clones contained organelle DNA. Furthermore, this library is representative and shows good genome coverage, as established by hybridisation screening of high-density filters using a number of nuclear probes distributed across the allotetraploid genome. This Arabica BAC library, the first large-insert DNA library so far constructed for the genus Coffea, is well-suited for many applications in genome research, including physical mapping, map-based cloning, functional and comparative genomics as well as polyploid genome analyses.Communicated by J.W. Snape     

Identification of P18, a surface protein produced by the fish pathogen Flavobacterium psychrophilum

AIMS: This study was focused on the identification of associated outer membrane proteins which may play a role in the specific interactions between Flavobacterium psychrophilum (the aetiological agent of cold-water disease and rainbow trout fry syndrome in salmonid fish worldwide) and the fish tissues. METHODS AND RESULTS: The surface protein interactions with the outer membrane being mainly ionic, different methods were used for the detachment of proteins from the cell surface of Fl. psychrophilum involving detergent-free buffers or solutions known to perturb the ionic interactions. Such treatments led to the isolation of a surface protein, named P18 in accordance with its relative molecular mass. The expression of P18 was not related to the growth conditions (liquid or solid medium, temperature and aeration) or the strains of Fl. psychrophilum tested here. CONCLUSIONS: Preliminary characterization indicated that P18 is a surface antigen which is not sugar-modified and might be a subunit of a surface layer (i.e. S-layer), one of the most common surface structures on bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: Data reported here should be used as the basis for further works involving the purification and characterization of P18 to identify the specific roles of such a surface protein, especially the interaction between this protein and the host surface.