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M Daudon

Publications and source records attributed to M Daudon.

At least 127 records · Page 7Linked to original sources
PubMed1983

[Detection and diagnosis of drug induced lithiasis].

Drug-induced calculi are often mis-diagnosed because of inadequate analysis of the urinary calculi. These stones can only be characterized unambiguously by global physical methods like infra-red spectrophotometry. From a series of 2,000 calculi analysed under infra-red, we identified 22, i.e. 1.1% of cases, which contained, partly or entirely, drug products. Ten other cases are still being studied. Amongst the products identified we found metabolites of glafenine (Glifanan) in 7 cases, triamterene and its derivatives (Cycloteriam) in 7 cases, metabolites of phenazopyridine (Pyridium) in 4 cases, sulphonamides in 2 cases : N-acetylsulphamethoxazole hydrochloride (Bactrim) and N-acetylsulphaguanidine (Guanidan), flumequine (Apurone) in 1 case and calcite (Cal-Mag-Na) in 1 case. The authors estimate that about 100,000 calculi are excreted in France each year and that at least 1,000 of these potentially contain drugs and are not diagnosed. Early recognition of drug induced stones is essential in order to protect the patient from recurrences, the risks of renal complications or, more simply, from useless therapeutic or dietetic regimes.

Antacids↗
PubMed1983

[Study of spontaneous crystalluria using infrared spectroscopy. Research on correlations between crystals, calculi, bacteria and the sex of the patients].

6 100 specimens of urine were examined according to classical cytobacteriological techniques for the presence of crystals and the possible correlations with the bacteria identified and the sex of the patients. When crystals were present, the urine was centrifuged and the deposit was dried in a filter with low porosity, scraped away and incorporated in a tablet of potassium bromide and then examined by infra-red spectrophotometry. Positive crystalluria was found in 6.4% of urines from patients without lithiasis and in 59% of cases with lithiasis. Only 50% of cases had a pure mineral type. Struvite was the most common (34.3%), then weddellite (33.1%), carbapatite (23.1%), amorphous calcium phosphate (22.7%) and ammonium urate (18.3%). Any of these compounds could be found pure or in combination with others. The other constituents were appreciably less common. All in all, 76 types of crystalluria were demonstrated. Important differences in crystallurias and the bacteria identified were detected as a function of the sex of the patients. Positive correlations were found between a number of bacteria and the crystals with which they are associated. The distribution and the composition of the cases of crystalluria were compared with those of urinary calculi.

Chemical Phenomena↗
PubMed1982

[Triamterene induced nephrolithiasis (author's transl)].

Various studies have demonstrated a relationship between nephrolithiasis and the ingestion of certain drugs. We are particularly interested in the effects of triamterene. Five published case studies on patients of both sexes between 43 and 60 years of age have proven that a regular consumption of normal doses of triamterene has a direct effect upon the formation of renal stones. The stones analysed by infra-red spectrophotometry during the above observations contained from 20 to 100% of triamterene and it's metabolite hydroxytriamterene, following a daily consumption of 150 to 350 mg during a period of 6 to 38 months. It has been confirmed that triamterene and it's metabolite hydroxytriamterene are very poorly soluble and super-saturate the urine for a brief period following the ingestion of the drug. Triamterene might also intervene in the initial phenomena of nucleation. It is therefore recommended that triamterene be used with caution in those patients presenting a history of nephrolithiasis. The existence of drug induced nephrolithiasis reinforces the importance of the technique of renal stone analysis, and the necessity of a systematic study of all renal stones found. This will allow us to develop the study of the correlations between the different episodes of renal stone disease, the nature of the treatment undertaken and the systematic analysis, layer by layer, of the stone.

Adult↗
PubMed1982

[Triamterene and renal calculi].

The authors report the detailed analysis of 4 calculi containing triamterene observed between 1979 and 1981. The composition of drug layers is almost the same in the 4 calculi and shows a mixture of triamterene (estimated at 35% of iatrogenic components) and 7 metabolites among them p-hydroxy-triamterene (5-10%) and mainly p-hydroxytriamterene estersulfate (40-55%). The authors hypothesize a metabolic or physicochemical relation between triamterene and uric acid which are frequently associated in these calculi that represent 0.4% of all lithiasis. An estimated 150 to 200 calculi with triamterene are probably eliminated though not detected every year in France. The interest of a fine analysis of calculi by appropriate physical methods, such as infrared spectrometry, is emphasized.

Adult↗
PubMed1982

[Metabolism-embryotoxicity relationship of febantel in the rat and the sheep].

The metabolism of febantel has been investigated in the rat and the sheep. The general pathway seems to be similar in both species: ten urinary metabolites are the result of cyclisation, oxidation and/or hydrolysis process. Using synthetic samples, the embryotoxic study of all individual metabolites has been performed in the rat. Unchanged febantel and two other metabolites are responsible for teratogenic effects. A four steps toxogenic pathway is described which finally leads to the ultimate known teratogen: methyl (5-(phenylsulfinyl)-1H-benzimidazole-2-yl) carbamate. Metabolic similarities with other anthelmintics and residual consequences are discussed.

Abnormalities, Drug-Induced↗
PubMed1980

Analysis of urinary calculi in adults. Attempt of correlations between morphology and composition.

The analysis of 322 urinary calculi in adults by microdissection, infrared spectromorphometry and microchemistry has shown that stones could be classified in several groups according to their morphology and composition: 8 morphological types have been defined (2 for the oxalic, 2 for the uric, 2 for the phosphatic and 2 for the cystinic stones). Correlations between morphology and composition have been established dividing the calculi into 10 categories, 4 for the pure forms and 6 for the mixed forms; the total includes approximately 94% of the calculi analyzed. An 11th category gathering various lithiases (rare or with multiple components) represents 6% of the cases. Moreover, the study of the localization of the component in stones emphasizes the high frequency of Ca phosphates in the nucleus of oxalic lithiases: 80% in mixed forms, in which the oxalate is the main constituent.

Adult↗
PubMed1980

[Renal pelvis stones made of glafenic acid in two patients under prolonged treatment with analgesics (author's transl)].

Two women aged 62 and 69 years who had been taking glafenine at normal dosage over a period of 4 years developed a renal calculus. In the first case, 6 small slightly radioopaque stones were extracted by pyelotomy, presenting a crystalline surface and yellow, soft, and amorphous section. They consisted of 50% calcium oxalate, 33% glafenic acid, and 10% proteins. In the second case, pyelography showed a sizable round and radiotransparent defect in the renal pelvis. At pyelotomy, a large, soft, and greenish stone was extracted, presenting a yellow and amorphous section, without calcium, but consisting of 75% glafenic acid, and 25% proteins. Through IR spectrography, glafenine metabolites found in the stones represented 33% in our first case and 75% in our second case. Through other methods, such as UV spectrophotometry and chromatography, 26% and 61% are respectively found. The metabolites are glafenic acid and hydroglafenic acid, in an identical proportion of 9 to 1 in both cases.

Aged↗
PubMed1978

[Analysis of gallstones by infrared spectrophotometry. Advantages and limits of the method (author's transl)].

Numerous clinicians criticise the insufficiency and imprecision, and the incoherency of the analyses of biological calculations by the usual clinical methods and thus frequently avoid prescribing such an examination. The authors propose the application of a physical method, infrared spectrophotometry for the qualitative and semi-quantitative determination of the composition of stones of all origins. They recall the often heterogeneous structure of the stones and emphasise the importance which they attribute of differential analysis by separate zones during careful dissection, the results of which may orient the therapeutic attitude of the clinician. The differentiation of a few crystalline structures and the study of complex mixtures are dealt with in the form of characteristic infrared spectra. The advantages and limits of the method compared with other technics of analysis are discussed.

Bilirubin↗
PubMedDate not supplied

Infrared analysis of urinary stones: a trial of automated identification.

A Search algorithm included in the Opus software of Bruker (Germany) was evaluated for analysis of urinary stones. Three reference libraries containing respectively 85 (single components), 1,059 (binary mixtures) and 4,565 (ternary mixture) digitized spectra were created and used to identify unknown spectra (n=320), applying the automatic procedure. Identification of the major component was correct in 83% of cases but the percentage of identification significantly decreased for the second and the third components. In cases of identification of the two first components, quantitative assessment was correct within tolerance limits +/- 15%. The computer results are judged unsatisfactory with regard to pathology because computer-aided identification is not sufficiently sensitive and specific to differentiate species with similar spectral pattern, even for the identification of main component, and also to detect minor components. It can be of assistance to guide spectral analysis, but it cannot replace human identification.

Algorithms↗
PubMedDate not supplied

[Clinical value of urinary biochemical parameters].

Twelve of the urine parameters, namely sodium, potassium, chloride, urea, creatinine, uric acid, calcium, phosphate, protein, microalbumin, amylase and glucose, routinely measured in a biochemistry laboratory were chosen to revalue their interest in clinical practice. For each parameter, urinary collection method, physiologic review and specific indications were set out. The clinical interest of chloride, urea, phosphate or uric acid measurement seem limited to specific pathological conditions. The measurement of urine amylase is out of interest.

Adolescent↗
PubMedDate not supplied

[Urinary lithiasis of medical origin].

Analysis of 22,510 urinary calculi between January 1991 to July 2000 performed by infrared spectroscopy allows for separation of drug-induced urolithiasis into two categories: first, the drugs physically embedded in the stone (n = 238; 1.0 per cent), notably indinavir monohydrate (n = 126; 52.9 per cent), followed by triamterene (n = 43; 18.1 per cent), sulphonamides (n = 29; 12.2 per cent) and amorphous silica (n = 24; 10.1 per cent); second, the category of metabolic nephrolithiasis induced by drugs (n = 140; 0.6 per cent), involving mainly calcium and vitamin D supplementation (n = 56; 40.0 per cent) and carbonic anhydrase inhibitors (n = 33; 23.6 per cent). Composition of the stone depended not only on the inducer drug but also on the metabolic state of the patient. Today, drug-induced stones comprise about 1.6 per cent of all calculi in France. Physical analysis and therapeutic history recall of such patients are the keys to diagnosis. Medical care is based on drug avoidance or dose adjustment with increased diuresis and, if necessary, change in urinary pH.

Drug-Related Side Effects and Adverse Reactions↗
PubMedDate not supplied

[Clinical value of crystalluria study].

Crystalluria is a marker of urine supersaturation present in both normal and pathological conditions. Indeed, nature and characteristics of the spontaneous crystalluria are of clinical interest for detecting and following biological disorders involved in renal diseases. Method. Crystalluria examination should preferably be performed on first morning urine or fresh fasting voiding samples by polarised microscopy in a Malassez cell. Urine samples must be stored at 37 degrees C or at room temperature and examined within two hours following voiding. Results and discussion. Crystalluria should be interpreted according to various criteria: 1) chemical nature of crystals for abnormal crystals such as struvite, ammonium urate, cystine, dihydroxyadenine, xanthine or drugs; 2) crystalline phase of common chemical species as calcium oxalates, calcium phosphates and uric acids; 3) crystal morphology (calcium oxalates); 4) crystal size (calcium oxalates); 5) crystal abundance (calcium oxalates, calcium phosphates, uric acids, cystine); 6) crystal aggregation (calcium oxalates); 7) frequency of crystalluria assessed on serial first morning urine samples, a very useful tool for long-term surveillance of patients. Within calcium oxalate crystalluria, presence of whewellite is a marker of elevated oxalate concentration (urine oxalate > 0.3 mmol/L); a crystal number > 200/mm 3 is highly suggestive of heavy hyperoxaluria of genetic or absorptive origin. Predominant weddellite crystalluria is most often indicative of an excessive urine calcium concentration (> 3.8 mmol/L); a dodecahedric aspect of the crystals is a marker for heavy hypercalciuria (> 6 mmol/L) while an increased crystal size (>or= 35 microm) is indicative of simultaneous hypercalciuria and hyperoxaluria. Calculation of the global crystal volume, especially when applied to calcium oxalates or cystine, is a clinically useful tool for the monitoring of patients suffering from primary hyperoxaluria or cystinuria. Lastly, presence of crystalluria in more than 50% of serial first voided morning urine samples is in our experience the most reliable biological marker for detecting the risk of stone recurrence in lithiasic patients. Conclusion. Crystalluria examination is an essential laboratory test for detecting and following pathological conditions, which may induce renal stone disease or alter kidney function due to urine crystals.

Biomarkers↗
PubMedDate not supplied

[Synchrotron radiation techniques for structural characterisation of biological entities: an example with renal stone analysis].

This paper describes the opportunities given by the synchrotron radiation techniques regarding the structural characterisation of biological entities. After a short recall on the characteristics of the synchrotron radiation, are described the experimental devices based on fluorescence X, wide angle X-ray scattering and X-ray absorption spectroscopy, which may applied for biological samples, especially in the field of stone analysis. Recent progresses in medical research using synchrotron radiation will be also discussed.

Crystallography, X-Ray↗