On the mode of action of the fungicide etridiazole

Etridiazole (5-ethoxy-3(trichloromethyl)-1,2,4-thiadiazole) is a fungicide primarily effective against fungi of the Oomycete group. After addition of the compound to the medium, growth of Mucor mucedo was impaired almost immediately. Oxygen uptake of the mycelia decreased only slightly at growth-inhibiting concentrations. Respiration of isolated mitochondria of Mucor was inhibited about 50% by high concentrations of the fungicide, while the respiratory control quotient remained constant. In contrast, rat liver mitochondria were not very sensitive to etridiazole. Etridiazole stimulates the hydrolysis of membrane-bound phospholipids to free fatty acids and lysophosphatides in isolated mitochondria of Mucor. Procaine, a well-known inhibitor of phospholipases, acts as an antidote for etridiazole in growth tests as well as in the hydrolysis of phosphatidylcholine by isolated mitochondria. Calcium ions in millimolar concentrations act like procaine. Therefore, it was assumed that the fungistatic effect of etridiazole was mainly caused by an activation of phospholipases in the mitochondrial membranes. Moreover, under the influence of etridiazole, a lipid peroxidation of membranes is observed. Tocopherol acts as an antidote. This could be the primary toxic effect in the mechanism of action of this fungicide. The enzymes involved are not yet identified.     

Recurrence of thoracolumbar intervertebral disk extrusion in chondrodystrophic dogs after surgical decompression with or without prophylactic fenestration: 265 cases (1995-1999)

OBJECTIVES: To evaluate a population of chondrodystrophic dogs treated for Hansen type 1 intervertebral disk (IVD) disease by surgical decompression with or without prophylactic fenestration and determine the rate and location of surgically confirmed recurrence of intervertebral disk extrusion. ANIMALS: 265 dogs. STUDY DESIGN: Retrospective study. PROCEDURES: Medical records of dogs that underwent spinal decompression between 1995 and 1999 were reviewed. RESULTS: 3 (4.9%) dogs were euthanatized or died prior to discharge. Fenestration was performed in 252 dogs, including 37 (14.7%) at the site of decompression only, 48 (19%) at 3 to 4 disk spaces, and 167 (66%) at 5 to 7 disk spaces. There were 12 instances of recurrent disk extrusion confirmed by removal of disk at a second surgery 3.5 to 33 months after the first surgery. Recurrence was always at a new disk space, and rates did not significantly differ between dogs that underwent single or multiple fenestrations. Two recurrences were at a previously fenestrated disk space. Seven recurrences were at a site immediately adjacent to a fenestrated disk space, and 5 recurrences were at L4-5. CONCLUSIONS AND CLINICAL RELEVANCE: Prophylactic fenestration is generally successful in preventing future disk extrusions at fenestrated disk spaces. Prospective evaluation is still required to determine whether fenestration decreases the overall rate of recurrence. Prophylactic fenestration could promote disk extrusion at adjacent, nonfenestrated disk spaces. This could have a substantial clinical impact if recurrence develops at L4-5.     

Global mineralogical and aqueous mars history derived from OMEGA/Mars Express data

Global mineralogical mapping of Mars by the Observatoire pour la Mineralogie, l'Eau, les Glaces et l'Activité (OMEGA) instrument on the European Space Agency's Mars Express spacecraft provides new information on Mars' geological and climatic history. Phyllosilicates formed by aqueous alteration very early in the planet's history (the "phyllocian" era) are found in the oldest terrains; sulfates were formed in a second era (the "theiikian" era) in an acidic environment. Beginning about 3.5 billion years ago, the last era (the "siderikian") is dominated by the formation of anhydrous ferric oxides in a slow superficial weathering, without liquid water playing a major role across the planet.