Idioventricular low frequency oscillation in QT interval responds univocally to RR confusing kinds of mental stress.

Seventeen male subjects, aged nineteen to twenty, went through a protocol including, while supine, relaxation at rest (10 min) and mental stress (MS) by a Kraepelin (arithmetic) test (5 min), as part of a larger study. With a polygraphic analog recording set-up we also collected a 1 ms - digital facsimile of a lead II-like thoracic ECG with maximum T-wave (Codas, Dataq Instr). Twenty-three stress responses were assigned to three classes according to known cardiotacho-, plethysmo-, and pneumo-graphic marks of "concentrated attention mainly," "emotion," or still "high emotion." During each setting the most stationary 3 min RR epoch in cardiotachogram was selected for joint RR & QT beat-by-beat variability study. RR and QT intervals were detected using a published algorithm. Conventional RR and QT Fourier autospectra were computed, while using RR*QT mean square coherence spectrum we detached the RR-independent, idioventricular (IV) fraction of QT low frequency (LF: 0.04-0.15 Hz) power of variability (IV QT-LF). IV QT-LF responded consistently to varieties of mental stress that confuse RR-LF or let QT-LF unchanged, best witnessing the cortically-issued ventricular adrenergic strain. Indeed, while emotion propels the same way all spectral variables above, concentrated attention increased (Wilcoxon) significantly IV QT-LF only (0.54-0.80 ms2) and decreased RR-LF (715-463 ms2). Findings hold promise of a non-invasive, high resolution Holter based monitoring of sympathetic status of myocardium, robust vis-à-vis of confusion caused by the autonomic interplay at sino-atrial node.

[The action of amphiphilic drugs on human fibroblasts in vitro. Their possible use in antiviral and antitumor chemotherapy]. / Observations sur l'action de quelques drogues amphiphiles sur les fibroblastes humains in vitro. Applications possibles en chimiothérapie antivirale et antitumorale.

The LDH cytotoxicity test is able to emphasize the stabilisation of human embryo fibroblast membranes, in vitro, by two amphiphilic drugs: the metomidate and the thymolol. The membrane stabilisation is emphasized by the reduced LDH externalization as compared with the untreated cells. The use of the LDH test for the selection of some natural complexes or synthetic drugs with membrane stabilising and potential antiviral activity is proposed. The inhibition of LDH by metomidate was recorded, as decreasing of the enzyme activity with increasing metomidate concentration. This fact explains the known lactic acid accumulation, under metomidate treatment of human subjects. The use of metomidate in classical cancer treatment potentiation is proposed instead of lactate externalization inhibitors, already used for this aim.

Respiratory pathogens in non-human primates with special reference to Corynebacterium ulcerans.

An investigation of 272 non-human primates (75 Macacca cynomolgus, 97 Macacca mulatta and 100 Cercopithecus aethiops) revealed a high incidence of respiratory disease caused by Corynebacterium ulcerans, Staphylococci, Diplococci and Streptococci. Escherichia coli was also found as a secondary invader. Most of the infections occurred during winter in Macaca cynomolgus and were caused by Corynebacterium ulcerans and Diplococcus pneumoniae. The C. ulcerans strains were phage type VI G. A phage type III C strain was isolated from a Macacca mulatta. The high incidence of C. ulcerans suggests that this organism plays a significant role in the pathology of respiratory disease in the non-human primate.