[Idiopathic left ventricular aneurysm presenting with ventricular tachycardia. A case report]. / Anévrisme ventriculaire gauche idiopathique révélé par une tachycardie ventriculaire. A propos d'un cas.

Left ventricular aneurysm presenting with ventricular tachycardia was observed in a 48 year old man. Aetiological investigation was negative. The differences between aneurysm and diverticulum and the aetiologies of aneurysms are discussed. The treatment of the arrhythmias caused by this condition is discussed with the help of a review of the literature.

Involvement of abscisic acid-dependent and -independent pathways in the upregulation of antioxidant enzyme activity during NaCl stress in cotton callus tissue.

The role of abscisic acid (ABA) in the signal transduction pathway associated with NaCl-induced up-regulation of antioxidant enzyme activity was examined in a NaCl-tolerant cotton callus cell line treated with NaCl, ABA, paraquat, or H2O2 in the presence and absence or fluridone, an inhibitor of terpene, and therefore, ABA synthesis. Treatment with NaCl resulted in a rapid increase (within 30 minutes) in the ABA levels of the callus tissue, and the NaCl, ABA, and paraquat treatments induced rapid increases in the activities of superoxide dismutase, catalase, peroxidase, and glutathione reductase. Pre-treatment with fluridone significantly suppressed the NaCl-induced increases, but only slightly delayed the increases in tissue subjected to exogenous ABA treatment. This implies that ABA is involved in the signal transduction pathway associated with the NaCl-induced up-regulation of these antioxidant enzymes. Pre-treatment with fluridone had no effect on the paraquat-induced increases, suggesting that these enzymes can also be up-regulated by a pathway other than the one mediated by ABA. Both the NaCl and paraquat treatments produced significant increases in the superoxide levels within the callus, but the increase resulting from the paraquat treatment was significantly higher than the increase resulting from the NaCl treatment. These data suggest that NaCl stress results in the production of reactive oxygen intermediates (ROI) which signals the induction of an ABA-dependent signaling pathway. The production of very high levels of ROI, such as those that occur with paraquat treatment or perhaps during periods of prolonged or extreme stress, may induce an ABA-independent signaling pathway.

[Endocarditis caused by Cardiobacterium hominis]. / Endocarditis à Cardiobacterium hominis.

The incidence of endocarditis due to Cardiobacterium hominis is probably underestimated because clinical presentations vary greatly and culture of this Gram negative germ is difficult. A 48-year-old man with a past history of post-streptococcic aortic regurgitation was hospitalized twice within 1 week for fever (38 degrees C) and junctional tachycardia which responded to amiodarone. Subsequently, infero-apical necrosis was documented. Based on the result of the laboratory tests, coronary embolism was suspected although 12 blood cultures were negative. The patient recovered well with a standard antibiotic treatment. Fifteen days later, the blood cultures revealed Cardiobacterium hominis. Antibiotic therapy was adapted and aortic valve replacement was programmed. Two months later the patient died from uncontrollable left heart failure. A 63-year-old man who had had mitral valve replacement 10 years earlier for Streptococcus mitis endocarditis was hospitalized for fever (38 degrees C) and a painful left calf. Phlebocavography eliminated deep vein thrombosis and a complete cardiac work-up was inconclusive. Endocarditis was suspected although blood cultures were negative. The patient was given oral penicillin and discharged after one week. Three months later, the patient was again febrile (38 degrees C) and suffered a cerebral vascular event. Fourteen days after blood sampling, cultures revealed Cardiobacterium hominis. The patient's haemodynamic status worsened and valve replacement with atrioplasty was performed. Outcome after 4 years follow-up has been favourable. Endocarditis due to Cardiobacterium hominis, a saprophitic germ of the upper airway and the female genital tract, has been reported in 64 cases in the literature. The clinical picture is often limited to fever and a heart murmur and laboratory tests show an accelerated erythrocyte sedimentation rate and hyperleukocytosis. Inflammatory type anaemia is often found due to the latency of the endocarditis. Complications are frequent and can be fatal due to massive pulmonary emboli, cerebral vascular events or irreversible heart failure. C. hominis is sensitive to amoxycillin and netilmicin. Surgical treatment of the valvulopathy is indicated.

Whispering-gallery mirrors: fabrication tolerances and the effects of surface imperfections.

Like all short-wavelength optics, whispering-gallery mirrors that are intended for use with soft x rays require a high-quality surface finish. A coupled-mode description of scatter in whispering-gallery mirrors provides a convenient way of understanding the effects of surface imperfections and of establishing fabrication tolerances. Different kinds of imperfection have different effects on mirror performance and can be tolerated to different degrees. Figure errors, for example, are not critical, but periodic toolmarks are potentially disastrous. The acceptable amounts of random waviness and microscopic roughness depend on the correlation lengths involved. Overall, the tolerances are strict but less severe than those for normal-incidence optics.

Protoplast production in Chondrus crispus gametophytes (gigartinales, rhodophyta).

Protoplasts were isolated from female gametophytes of Chondrus crispus (Stackh.) using commercial cellulase and various carrageenases prepared from marine bacteria. Depending on the nature of the donor tissue (apices or whole thallus, wild or cultivated strains), yields ranged from 1.0-8.5×10(8) protoplasts per gram of fresh tissue. Preincubating the tissue with a potassium chelator, Kryptofix 222, enhanced protoplast yields by 30-50 %. Based on staining with fluorescein diacetate most protoplasts were viable. A few protoplasts regenerated a cell wall and divided.

[Post-concussion syndrome after cranio-cervical injuries. Apropos of a case]. / Syndrome post-commotionnel après traumatisme cranio-cervical. A propos d'une observation.

The post-concussion of the brain syndrome is an often observed clinical entity. In this especially subjective syndrome, one new pathogenic approach seems very interesting for the clinical and therapeutic conclusions. This is one medical case reported for the proof of this hypothesis.