Effect of dipyridamole on glomerular mesangial cell ecto-5′-nucleotidase expression

Although dipyridamole has been extensively studied as an anti-aggregating agent, its mechanism of action has not been elucidated. Cultured mesangial cells were treated with dipyridamole 1–100 M from 6–72 h. Ecto-5-nucleotidase activity approximately doubled (from 115±11 to 226±14 nmol/min/mg) after treatment with 100 M dipyridamole for 72 h. This effect was concentration- and time-dependent. Cycloheximide, an inhibitor of protein synthesis, did not alter basal 5-nucleotidase activity. However, it prevented stimulation by 5 M dipyridamole. Adenosine availability at the receptor sites was increased by dipyridamole and S-(p-nitrobenzyl)-6-thioinosine (NBTI), which inhibit adenosine uptake into the cell. Addition of dipyridamole or NBTI to the adenosine-treated mesagial cells produced an additive increase in ecto-5-nucleotidase activity. Dipyridamole, through its effect on extracellular adenosine and ecto-5-nucleotidase, may have an influence upon regulation of the glomerular microcirculation.     

Binding ofLens culinaris lectin to sea urchin embryo chromatin

Summary Lentin binds specifically to sea urchin embryo chromatin. This binding is saturable and inhibited by -methylmannose. Scatchard plot analysis of the binding reaction suggests a single binding site.     

Bone marrow in male and female rats

Summary Sex differences of high significance in the marrow weight relative to femur volume, as well as to body weight, were found in adult rats. A positive significant correlation was found between the femur volume and the marrow volume in both sexes, while a negative significant correlation between femur density and the marrow content (mg/mm³) exists only in male rats.     

Correlation between the carcinogenicity of organic substances and their spectral characteristics

Summary A correlation between the carcinogenicity of organic substances and their UV-absorption characteristics has been established. It is found that chemical carcinogens have absorption maxima in the wavelength region of 206–248 nm. On the basis of revealed correlation, a mechanism of chemical carcinogenesis is proposed.     

Simple theoretical criterion of chemical carcinogenicity

Summary The correlation between the average quasi-valence number and carcinogenicity of organic compounds has been established and discussed.     

Sur les variations stressogènes quantitatives de la sérotonine dans le cerveau

Zusammenfassung Das zerebrale Serotonin unterliegt im Verlaufe eines emotionellen Stress bedeutenden quantitativen Veränderungen. Bei Wildhasen, welche 14 Tage lang Schreckzeichen ausgesetzt waren, vermehrte sich die Menge des Serotonins und erreichte ihr Maximum am 7. Tag. Nachher sinkt die Menge unter den Normalwert, um am Ende der zweiten Woche wieder anzusteigen, wobei sie unter dem Normalwert bleibt.     

Dance reveals symmetry especially in young men

Dance is believed to be important in the courtship of a variety of species, including humans, but nothing is known about what dance reveals about the underlying phenotypic--or genotypic--quality of the dancer. One measure of quality in evolutionary studies is the degree of bodily symmetry (fluctuating asymmetry, FA), because it measures developmental stability. Does dance quality reveal FA to the observer and is the effect stronger for male dancers than female? To answer these questions, we chose a population that has been measured twice for FA since 1996 (ref. 9) in a society (Jamaican) in which dancing is important in the lives of both sexes. Motion-capture cameras created controlled stimuli (in the form of videos) that isolated dance movements from all other aspects of visual appearance (including FA), and the same population evaluated these videos for dancing ability. Here we report that there are strong positive associations between symmetry and dancing ability, and these associations were stronger in men than in women. In addition, women rate dances by symmetrical men relatively more positively than do men, and more-symmetrical men value symmetry in women dancers more than do less-symmetrical men. In summary, dance in Jamaica seems to show evidence of sexual selection and to reveal important information about the dancer.     

Major contribution of codominant CD8 and CD4 T cell epitopes to the human cytomegalovirus-specific T cell repertoire

Human cytomegalovirus (HCMV) infection or reactivation is a cause of morbidity and mortality in immunocompromised individuals. In immunocompetent individuals, in contrast, HCMV is successfully controlled by specific CD8 and CD4 T cells. Knowledge of CD8 and CD4 T cell epitopes from HCMV and their immunodominant features is crucial for the generation of epitope-specific T cells for adoptive immunotherapy and for the development of a peptide-based HCMV vaccine. Therefore, we investigated the natural frequencies of a large number of CD8 and CD4 T cell epitopes, including 10 novel ones. We determined several epitopes as immunodominant. Surprisingly, no clear hierarchies were found for CD8 T cell epitopes, indicating codominance. These results will be valuable for adoptive transfer strategies and support initiatives towards development of a peptide-based HCMV vaccine.Received 12 August 2004; received after revision 24 September 2004; accepted 29 October 2004 These authors contributed equally to this work.     

Effect of adrenal function on level of hepatic and extrahepatic arginase

Résumé On a constaté que l'arginase des reins est plus sensible que l'arginase du foie a l'hydrocortisone injecté. Au contraire, l'adrénalectomie provoque la réduction de l'activité arginasique du foie mais ne modifie pas le niveau de l'arginase rénale.     

Changes in electrical activity of the cockroachBlatta orientalis L. brain induced by anti-lobster brain antibody

Zusammenfassung Bei mit Langustenhirn immunisierten Kaninchen werden Anti-Hirn-Antikörper gebildet. Werden diese auf die Hirnoberfläche der SchabeBlatta orientalis L. gebracht, so kommt es zu erheblichen Veränderungen in der elektrischen Hirntätigkeit des Insekts.