Demonstration of anti-hydralazine antibody in hydralazine inducedLupus erythematosus

Résumé La présence d'un facteur anti-hydralazine, probablement un anticorps, a été démontrée par l'emploi d'une technique d'hémagglutination dans le sérum d'un malade qui manifestait des symptômes de lupus érythémateux après un long traitement avec de l'hydralazine. Le même facteur anti-hydralazine a été observé dans le sérum des lapins qui avaient reçu des injections répétées d'émulsion d'hydralazine dans un adjuvant.     

Anomalous 17O compositions in massive sulphate deposits on the Earth

The variation of delta 18O that results from nearly all physical, biological and chemical processes on the Earth is approximately twice as large as the variation of delta 17O. This so-called 'mass-dependent' fractionation is well documented in terrestrial minerals. Evidence for 'mass-independent' fractionation (delta 17O = delta 17O-0.52 delta 18O), where deviation from this tight relationship occurs, has so far been found only in meteoritic material and a few terrestrial atmospheric substances. In the rock record it is thought that oxygen isotopes have followed a mass-dependent relationship for at least the past 3.7 billion years, and no exception to this has been encountered for terrestrial solids. Here, however, we report oxygen-isotope values of two massive sulphate mineral deposits, which formed in surface environments on the Earth but show large isotopic anomalies (delta 17O up to 4.6%). These massive sulphate deposits are gypcretes from the central Namib Desert and the sulphate-bearing Miocene volcanic ash-beds in North America. The source of this isotope anomaly might be related to sulphur oxidation reactions in the atmosphere and therefore enable tracing of such oxidation. These findings also support the possibility of a chemical origin of variable isotope anomalies on other planets, such as Mars.     

Zur kompensatorischen Nierenregeneration. Autoradiographische Untersuchungen nach3H-Thymidin-Dauerinfusion

Summary By continuous infusion of³H-thymidine, autoradiographic studies were performed to compare cellular proliferation in the compensatory regenerating kidney of rats after contralateral nephrectomy or contralateral temporal (1 h) ischaemia with physiological cell renewal in controls. Under each experimental condition, the highest labelling index is observed within the stratum labyrinthicum and then a gradual decrease occurs from there to the stratum subcorticale, zona intermedia and basalis. As to the topic of DNA synthesizing cells in the different zones of the kidney, there are only quantitative differences between physiological cell renewal of the controls and compensatory regeneration following contralateral nephrectomy and contralateral ischaemia.

---

---

Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

ATM phosphorylation of Nijmegen breakage syndrome protein is required in a DNA damage response

Nijmegen breakage syndrome (NBS) is characterized by extreme radiation sensitivity, chromosomal instability and cancer. The phenotypes are similar to those of ataxia telangiectasia mutated (ATM) disease, where there is a deficiency in a protein kinase that is activated by DNA damage, indicating that the Nbs and Atm proteins may participate in common pathways. Here we report that Nbs is specifically phosphorylated in response to gamma-radiation, ultraviolet light and exposure to hydroxyurea. Phosphorylation of Nbs mediated by gamma-radiation, but not that induced by hydroxyurea or ultraviolet light, was markedly reduced in ATM cells. In vivo, Nbs was phosphorylated on many serine residues, of which S343, S397 and S615 were phosphorylated by Atm in vitro. At least two of these sites were underphosphorylated in ATM cells. Inactivation of these serines by mutation partially abrogated Atm-dependent phosphorylation. Reconstituting NBS cells with a mutant form of Nbs that cannot be phosphorylated at selected, ATM-dependent serine residues led to a specific reduction in clonogenic survival after gamma-radiation. Thus, phosphorylation of Nbs by Atm is critical for certain responses of human cells to DNA damage.     

Blood pressure lowering effect of eicosapentaenoic acid-rich diet in normotensive, hypertensive and hyperlipemic subjects

A mackerel diet or a herring diet in which two cans of fish fillet were consumed daily over 2 weeks within a prescribed regimen, in a crossover design, were given to 15 normotensive volunteers, 14 patients with mild essential hypertension and eight patients with type IV and V hyperlipoproteinemia (HLP). In normotensives a markedly lower systolic and diastolic blood pressure at the end of the period on the mackerel diet could be observed, whereas in hypertensive and hyperlipemic subjects only systolic blood pressure was significantly decreased. After the herring diet, which served as control, changes in blood pressure were of a minor degree.