Iridoids. A review.

Tre review presents a glossary of the iridoid glycosides, secoiridoids, bis-iridoids, and non-glycosidic iridoids. The following information is present for each compound, when available: structural formula, molecular formula, molecular weight, mp and [alpha]D values, uv, ir, 1H-nmr, 13C-nmr, and ms data, as well as mp and [alpha]D values for the correspondent acetate derivative. The natural source, the family and generic name, is given as well as the reference. A cross index and molecular weight tables are presented.

[Anesthesia for surgery of degenerative and abnormal cervical spine]. / Anesthésie pour chirurgie du rachis cervical dégénératif et malformatif.

A feature common to all congenital or inflammatory abnormalities of the cervical spine is an actual or potential reduction in the lumen of the spinal canal. The spinal cord and nerve roots are at risk. During intubation, and positioning the patient on the table, all untoward movements of the cervical spine may lead to spinal cord compression. Abnormalities of the cervical spine carry the risk of a difficult intubation. If there is much debate as to what constitutes optimum management of the airway, there is no evidence that any one method is the best. Recognizing the possible instability and intubating with care, are probably much more important in preserving neurological function than any particular mode of intubation. During maintenance of anaesthesia, the main goal is to preserve adequate spinal cord perfusion in order to prevent further damage. Spinal cord blood flow seems to be regulated by the same factors as cerebral blood flow. Hypercapnia increases cord blood flow while hypocapnia decreases it. Therefore, normocapnia or mild hypocapnia is recommended. Induced hypotension is frequently used to decrease blood loss. However, in patients with a marginally perfused spinal cord, the reduction in blood flow may cause ischaemia of the spinal cord and may therefore be relatively contraindicated. In addition to standard intraoperative monitoring, spinal cord monitoring is almost mandatory. Monitoring somatosensory evoked potentials is used routinely. However, the major limitation is that this technique only monitors dorsal column function; theoretically, motor paralysis can occur despite a lack of change in recorded signals. Neurogenic motor evoked potentials may now be used to monitor anterior spinal cord integrity.(ABSTRACT TRUNCATED AT 250 WORDS)

[Systemic toxicity of local anesthetics. Pharmacokinetic and pharmacodynamic factors]. / Toxicité systémique des anesthésiques locaux. Facteurs pharmacocinétiques et pharmacodynamiques.

Local anaesthetics can have systemic adverse effects, mostly affecting the central nervous system and the heart. The physicochemical characteristics of the different local anaesthetics are recalled, for they determine the relationship between structure, activity and toxicity. The pharmacokinetic factors involved in the toxic effects of local anaesthetics, whether the drug is given in a single extravascular dose or, accidentally, within a blood vessel, are discussed. The toxic effects of repeated administrations of local anaesthetics depend on the metabolism of the drug as well as on pharmacokinetic factors. Possible maximal doses and drug interactions are also discussed. The mechanism of action of local anaesthetics, which block the sodium channel, explains their tissue toxicity and, more specifically, their central nervous and cardiovascular toxicities, which are more pronounced for the more potent local anaesthetic agents (bupivacaine, etidocaine). Systemic maternal effects and transplacental passage probably explain their foetal toxicity. Specific toxic effects are seen with some drugs, such as methaemoglobinaemia and allergic reactions (rarely for amide agents). Overall, local anaesthetic accidents are rare, but they must be prevented.

[Acute intracranial subdural hematoma of arterial origin after spinal anesthesia]. / Hématome sous-dural aigu intracrânien d'origine artérielle après rachianesthésie.

A case of an acute intracranial subdural haematoma occurring shortly after spinal anaesthesia is reported. A 67 year old poorly controlled hypertensive man, ASA II, underwent removal of a prostatic adenoma under spinal anaesthesia. He complained of postural headache on the third day after surgery. Unresponsive to the usual analgesics, his headache became severe, persistent and non postural on the fifth day. Twenty-four hours later, he suddenly presented with a left hemiplegia and became comatose. Computed axial tomography showed a large left-sided subdural haematoma, lying over the left hemisphere. During the immediate surgical removal, a pulsatile arterial bleeding originating from a small cortical artery was discovered, and stopped. The patient slowly recovered consciousness, but the hemiplegia remained. He finally died six months later of bronchopneumonia. The link between the haematoma and the spinal anaesthetic is not proven; the possible relationship between the two is discussed.

Determination of pindolol enantiomers in human plasma and urine by simple liquid-liquid extraction and high-performance liquid chromatography.

A simple method for the measurement of pindolol enantiomers by HPLC is presented. Alkalinized serum or urine is extracted with ethyl acetate and the residue remaining after evaporation of the organic layer is then derivatised with (S)-(-)-alpha-methylbenzyl isocyanate. The diastereoisomers of derivatised pindolol and metoprolol (internal standard) are separated by high-performance liquid chromatography (HPLC) using a C18 silica column and detected using fluorescence (excitation gamma: 215 nm, emission gamma: 320 nm). The assay displays reproducible linearity for pindolol enantiomers with a correlation coefficient of r2> or =0.998 over the concentration range 8-100 ng ml(-1) for plasma and 0.1-2.5 microg ml(-1) for urine. The coefficient of variation for accuracy and precision of the quality control samples for both plasma and urine are consistently <10%. Assay parameters are similar to those of previously published assays for pindolol enantiomers, however this assay is significantly easier and cheaper to run. Clinically relevant concentrations of each pindolol enantiomer can readily be measured.