Laser angioplasty in peripheral arterial disease

Laser angioplasty was performed in 66 patients with total occlusion of the ilio-femoral artery. The system used consisted of a pulsed dye laser operating at 480 nm, 50 mJ pulse^–1, 2s pulse^–1 and 5 Hz. The treatment laser was coupled into a 200m optical fibre wrapped around a coil for improved flexibility and radiopacity. The treatment laser was connected with a diagnostic laser consisting of a continuous wave helium-cadmium laser operating at 325 nm, 50 ms and 3 mW for tissue detection using fluorescence spectroscopy. The primary success rate was 82%, the complication rate was 15% without any clinical sequelae and the 18 month follow-up patency rate was 64%. Due to the narrow pilot channel created by laser angioplasty, in each case a complementary balloon angioplasty was required to restore the arterial lumen. The success rate did not depend upon the length of occlusion but was rather related to the extent of calcification. Laser angioplasty guided by spectroscopy is effective and safe in patients with totally occluded peripheral arteries in whom mechanical devices failed to cross the obstruction.     

Mapping of c-fos gene expression in the brain during morphine dependence and precipitated withdrawal, and phenotypic identification of the striatal neurons involved

The c-fos gene is expressed in the central nervous system in response to various neuronal stimuli. Using in situ hybridization, we examined the effects of chronic morphine treatment and withdrawal on c-fos mRNA in the rat brain, and particularly within identified striatal neurons. Morphine dependence was induced by subcutaneous implantation of two pellets of morphine for 6 days and withdrawal was precipitated by administration of naltrexone. Placebo animals and morphine-dependent rats showed a very weak c-fos mRNA expression in all the structures studied. Our study emphasized the spatial variations in c-fos mRNA expression, and also revealed a peak expression of c-fos mRNA at 1 h after naltrexone-precipitated withdrawal in the projection areas of dopaminergic neurons, noradrenergic neurons and in several regions expressing opiate receptors. Interestingly, morphine withdrawal induces c-fos mRNA expression in the two efferent populations of the striatum (i.e. striatonigral and striatopallidal neurons) both in the caudate putamen and nucleus accumbens. Moreover, the proportions of activated neurons during morphine withdrawal are different in the caudate putamen (mostly in striatopallidal neurons) and in the shell and core parts of the nucleus accumbens (mostly in striatonigral neurons). The activation of striatopallidal neurons suggests a predominant dopaminergic regulation on c-fos gene expression in the striatum during withdrawal. On the contrary, c-fos induction in striatonigral neurons during withdrawal seems to involve a more complex regulation like opioid-dopamine interactions via the mu opioid receptor and the D1 dopamine receptor coexpressed on this neuronal population or the implication of other neurotransmitter systems.     

Duration of antibiotic treatment in intensive care: current data

OBJECTIVE: To review the current data on the duration of an antibiotic treatment. METHODS: Analysis of recent and older articles on criteria of discontinuation of an antibiotic treatment in intensive care patients. SYNTHESIS: In intensive care patients the initiation of an antibiotic therapy is more or less codified, in spite of numerous existing problems. The duration of its maintenance, although based on scientific data depends mainly on a multitude of variables. The first step is to assess the therapeutic efficiency in considering the regression of clinical manifestations, the normalization of the acute phase reactants, the sterility of bacteriological samples and the absence of relapse at therapy discontinuation. An assessment after 48 hours is essential, in order to decide the maintenance or the modification of therapy. Finally the indication of bitherapy is considered. The theoretical duration of antibiotic therapy is determined in taking into account the involved microbial agent(s), the centre of infection, the bacterial inoculum, the patient, the presence of foreign material, and the administered antibiotic.     

Prevalence of methicillin-resistant Staphylococcus aureus nasal carriage among patients with femoral neck fractures: implication for antibiotic prophylaxis.

Fifteen (8.4%) of 179 patients admitted with femoral neck fractures carried MRSA. Among 96 patients admitted from their homes, only 2 (2%) were carriers, whereas 13 (15.6%) of 83 patients from nursing or residential homes or long-term-care facilities were colonized (P = .001). Routine prophylaxis with vancomycin is recommended in the latter group.     

Localisation of drug permeability along the rat small intestine, using markers of the paracellular, transcellular and some transporter routes

The small intestine is the major site of drug absorption. Some reports in the literature have evoked the concept of “absorption windows” in the small intestine: are there specific regions where drug absorption is significantly higher than others? To investigate this question, we used an everted gut sac method to study the permeability of drugs and markers every 3–4 cm down the entire small intestine in rat. These markers were chosen to be representative of the mechanisms by which drugs cross the small intestinal mucosa: paracellular and transcellular passive diffusion, via influx transporters, and a drug (digoxin) that is effluxed from cells by P-glycoprotein (P-gp). The passive diffusion and influx transporter markers gave similar profiles with a plateau of permeability along the jejunum, and with the exception of L-Dopa, lower permeability in the ileum. Digoxin showed a linear decrease in the profile from the proximal jejunum to the ileum. Permeability in the duodenum was two to three times lower than the jejunum for all compounds. There were no narrow specific regions of high permeability and so the concept of discrete “absorption windows” along the small intestine as suggested from some pharmacokinetic studies may be related to other effects such as pH and/or solubility.