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C Moesch

Publications and source records attributed to C Moesch.

At least 19 recordsLinked to original sources
PubMed2006

[Inductively coupled plasma mass spectrometry. Perspectives in analysis and in biology].

ICP-MS is an instrumental method of multi-elementary qualitative and quantitative analysis. It associates with a mass spectrometer (MS) an ion source composed of a plasma torch fed with inductive coupling with a high frequency electromagnetic generator (ICP), similar to that used as a light source in highly-successful Atomics Emission Spectrometry (AES). ICP-MS can be applied to simultaneous analysis of numerous metallic and metalloid elements (80 or so). Its sensitiveness is all in all far better than that available with previous spectrometric techniques, which nevertheless remain more advantageous for processing certain low atomic mass elements. Thanks to its broad dynamic range, ICP-MS allows quantification of an array of elementary concentrations within a single sample. ICP-MS offers particularly interesting perspectives in geochemistry and metal processing, as well as in biochemistry and food or toxicology and environmental analysis. Implementation is rapid and the technique is suitable for series or continuous analyses, or for analysis of any evolving medium such as effluents from gas or liquid chromatography or from capillary electrophoresis, making it a valuable tool for speciation analyses. Finally it enables non-radioactive isotopic labeling, essential for nutritional studies of trace elements, and sufficiently accurate isotopic dilutions, even with more accessible machines.

Animals↗
PubMed2005

Determination of chromium in whole blood by DRC-ICP-MS: spectral and non-spectral interferences.

Quantification of chromium in whole blood has been performed by ICP-quadrupole MS. The spectrometer was equipped with a dynamic reaction cell (DRC) with ammonia as reaction gas. The rejection parameter q (RPq) of the DRC and the flow rate of ammonia (NH3) were optimized and set at 0.7 and 0.6 mL min(-1), respectively. Blood was diluted 1:51 (v/v) with an aqueous solution containing 0.1 mg L(-1) NH4OH, 0.1 g L(-1) EDTA, 5 mg L(-1) n-butanol, and 0.1 per thousand Triton X100. Non-spectral matrix effects observed when using the DRC were confirmed by use of vanadium. External calibration with blank and standard solutions prepared in purified water led to biased results for quality control samples. Standard addition calibration was therefore used and its validity verified. By comparing the slopes and calculating residues, it was proved that the plot obtained with standard additions and the plot obtained from blood samples of different concentrations were aligned down to 0.05 microg L(-1) after dilution.

1-Butanol↗
PubMed2000

Polyethylene stent blockage: a porcine model.

BACKGROUND: Endoscopic insertion of biliary stents is a useful treatment for obstructive jaundice resulting from unresectable tumors of the pancreas and biliary tree. The main drawback is the recurrence of jaundice due to clogging. The aim of this study was to establish an experimental model of polyethylene stent clogging in large white pigs. METHODS: A straight polyethylene stent of 5F (group I), 7F (group II) or 10F size (group III) was inserted in the common bile duct. Animals were killed at 2 months, or earlier if physical signs suggesting stent clogging occurred. Chemicophysical analysis of stent deposition combined stereomicroscopy and identification of the contents by means of Fourrier transform infrared spectroscopy. Bacteriologic analyses included identification of aerobic and anaerobic bacteria and measurement of beta-glucuronidase, lecithinase and lipase activities. RESULTS: Physical signs suggesting stent obstruction or death occurred in 8 of 8 animals in group I, 11 of 12 in group II, and 2 of 8 in group III (p < 0.001). The proportion of mucoprotein in the stent contents tended to fall with increasing stent diameter (mean 82%, 58% and 47% for 5F, 7F and 10F, respectively), whereas wheat starch and calcium bilirubinate content increased with increasing stent diameter (9% and 4%, 18% and 10%, and 29% and 23% for 5F, 7 F, and 10F, respectively), although none of these differences were statistically significant. A variety of bacteria were cultured from the stent deposits, including anaerobic strains. Clostridium species were associated with the highest enzyme activities. CONCLUSIONS: In this model the major component of early stent deposits was mucoprotein, and numerous aerobic and anaerobic bacteria were isolated. Formation of calcium bilirubinate was a late phenomenon and poorly related to bacterial enzymatic activities.

Animals↗
PubMed2000

Prevention of biliary stent occlusion by ursodeoxycholic acid plus norfloxacin: a multicenter randomized trial.

We report a prospective randomized multicenter trial that tested the efficacy of combining ursodeoxycholic acid and norfloxacin in the prevention of polyethylene stent clogging in patients with obstructive jaundice due to an unresectable malignancy at the level of the common bile duct. After insertion of a 10-Fr straight polyethylene stent, patients were allocated to receive oral treatment with ursodeoxycholic acid and norfloxacin, or conservative treatment. The primary outcome measure was stent blockage within six months. Thirty-three patients (group I) received ursodeoxycholic acid and norfloxacin, and 29 received conservative treatment (group II). At six months, cumulative stent patency rate did not differ significantly between group I (47+/-11%, mean +/- SE, median 149 days) and group II patients (24+/-10%, mean +/- SE, median 100 days, P = 0.23, log-rank test). Four stents were clogged by ursodeoxycholic acid. Survival did not differ between the two groups. Combined therapy with ursodeoxycholic acid and norfloxacin failed to improve stent patency. Moreover, ursodeoxycholic acid can cause stent obstruction.

Aged↗
PubMed1997

Recurrence of biliary drug lithiasis due to dipyridamole.

The occurrence of drug-containing gallstones is not often observed. To our knowledge, three drugs have so far been incriminated-ceftriaxone, glaphenine, and dipyridamole. This report presents the case of an 85-year-old woman who developed a recurrent drug-containing gallstone caused by dipyridamole eighteen months after a previous stone had been removed endoscopically.

Aged↗
PubMed1995

Calcium oxalate crystalluria in elderly patients and treatment with naftidrofuryl oxalate.

Crystalluria is important in the evaluation of patients with urinary stone and is more frequently encountered in elderly than in younger adults. After noting that calcium oxalate monohydrate crystalluria was higher in elderly patients, we undertook a study to determine if oral treatment with naftidrofuryl oxalate, a drug frequently prescribed for elderly patients in France, was associated with crystalluria. The presence of early morning crystalluria was assessed in non-stone-forming patients hospitalized in a geriatric department. We studied 251 patients without a history of nephrolithiasis (mean age; 81.6 +/- 8.5 years) of whom 49 had been treated orally with naftidrofuryl oxalate at a mean dosage of 485 +/- 120 mg/24h. We identified and quantified the crystals in one early morning urine sample kept at room temperature. The frequency of crystalluria in elderly patients without stones who were not taking naftidrofuryl oxalate was 31.7% compared with only 6% in the general adult population. In this group, mainly calcium phosphate crystals were found. In patients who received naftidrofuryl oxalate, the frequency of crystalluria was 51% of which the major component was calcium oxalate monohydrate and not calcium phosphate. Naftidrofuryl oxalate may enhance crystal formation in elderly patients. This should be taken into account, particularly when other predisposing factors for nephrolithiasis are present, and a preventive increase in fluid intake considered.

Administration, Oral↗
PubMed1995

Potential nephrotoxicity of intravenous infusions of naftidrofuryl oxalate.

We report two cases of acute renal failure in patients with arteriosclerosis obliterans treated by intravenous infusion of naftidrofuryl oxalate. At renal biopsy the histological lesions were identical with those found in ARF due to hyperoxaluria of other causes, revealing tubular epithelial necrosis and massive intratubular precipitation of calcium oxalate monohydrate (C1) crystals. A second study was then conducted in four other patients with arteriosclerosis obliterans to evaluate serum and urinary levels of oxalate, and crystalluria during the intravenous administration of 800 mg of naftidrofuryl oxalate per day for 10 days. During the course of treatment, the serum and urinary oxalate levels were found to increase substantially, with the gradual onset of massive C1 crystalluria. These results indicate that naftidrofuryl oxalate was responsible for the acute renal failure in the first two patients. High intravenous doses of naftidrofuryl oxalate must be used cautiously, with close surveillance of renal function.

Acute Kidney Injury↗
PubMed1993

Glaphenine-containing gallstones.

Glaphenine is an analgesic drug derived from anthranilic acid. We report the analytical procedures for stone analysis in three cases of common bile duct stones containing glaphenic acid, which developed in arthrosic patients treated for 13.7 +/- 5 years with glaphenine. Stone analysis was performed by infrared spectroscopy, high performance thin layer chromatography, scanning electron microscopy and energy dispersive X-ray analysis. Mechanisms of lithogenesis are discussed. These observations emphasize the possibility of radiolucent gallstones mainly composed of drug compounds.

Aged↗
PubMed1991

Physicochemical and bacteriological analysis of the contents of occluded biliary endoprostheses.

The deposits obstructing 12 biliary endoprostheses were examined by scanning electron microscopy and analyzed quantitatively by Fourier transform infrared spectroscopy. Calcium palmitate and bilirubinate associated with proteins were found in all the deposits. Apart from the small amount of cholesterol, this composition closely resembled that of brown pigment gallstones and suggested an infectious cause. Facultative aero-anaerobic organisms were found on bacteriological investigation. beta-Glucuronidase activity was only detected in one sample, suggesting that the calcium bilirubinate may have been formed through tissue glucuronidases. In our study, deposit formation was thought to have been caused by the action of bacterial phospholipases (although not measured) rather than beta-glucuronidases.

Aged↗
PubMed1990

Spectroscopic analysis of charge transfer complexes between morpholine and iodine.

It has been demonstrated spectroscopically that many nitrogen-containing heterocyclic compounds can form charge transfer complexes with iodine. The complexes of morpholine with iodine were shown to be of the n-sigma type with a 1:1 stoichiometry. A strong donor-acceptor interaction was found (Kc = 1261 +/- 12 mol-1 at 20 degrees C in CCl4), considerably higher than those of complexes of aromatic compounds with iodine. The high value of the formation constant for this complex indicated that morpholine could serve as a starting point for the synthesis of novel anti-thyroid drugs.

Antithyroid Agents↗
PubMed1990

[Urinary lithiasis due to triamterene].

Iatrogenic renal stones although rare, must be diagnosed. It is therefore essential to use modern techniques such as infrared spectrophotometry. We report a new case of renal stones due to triamterene. Various predisposing factors are examined, in particular urine acidity and the presence of protein in the stones.

Aged↗