[Cystine lithiasis: study of a series of 116 cases]. / Lithiase cystinique: enseignements de l'étude d'une série de 116 cas.

INTRODUCTION: Cystine stones is a rare disease, related to a genetic metabolic disease. Its management must treat both the stones and their complications, and prevent recurrences by controlling cystinuria. OBJECTIVE: The objective of this study was to define the natural history of cystine stones, identify reliable diagnostic criteria and propose a simple treatment regimen. MATERIAL AND METHOD: The authors studied the clinical, biochemical and radiological data of a retrospective series of 116 cases, treated by the same urologist between 1953 and 1999. RESULTS: Cystinuria is often diagnosed in young adults on the basis of urine biochemistry (Brand's reaction, urinary cystine assay) or spectrophotometric analysis of the stones or urinary crystals. This assessment, not performed routinely, must be guided by a family history, recurrent stones or following failure of lithotripsy. The appearance of the stones, macroscopically a waxy yellow, radiologically only slightly opaque with a large component in the renal pelvis associated with a small round caliceal stones, is highly suggestive. Radiological assessment by IVU is generally sufficient. Treatment of the disease is medical and surgical: dietary measures, alkalinization of the urine and possibly drug treatments, are associated with extracorporeal lithotripsy or surgical treatment. These modalities eliminate cystine stones in 70% of cases. Recurrent stones are observed in 42% of cases followed for more than 5 years, mainly due to the presence of residual fragments (60% of recurrences). Surveillance and dietary measures must be maintained for life. Surveillance is based on biannual radiographic follow-up (plain x-rays +/- ultrasound) to detect and consequently treat small stones. A test for cystinuria must be proposed to all relatives of affected patients. CONCLUSION: This disease presents very polymorphic clinical features and clinical course. It can be responsible for impaired renal function and must therefore be investigated in the presence of suggestive clinical signs or history to avoid a delayed diagnosis, as treatment modalities are available to decrease the frequency of recurrence and which can potentiate treatment by surgical or lithotripsy. However, there are no predictive factors of deterioration of the disease, and biannual surveillance, for life, is essential to detect and treat small stones.

Ferrocyanide ingestion may cause false positives in cyanide determination.

CASE REPORT: The authors present a patient who ingested a cyanide containing solution and arrived at the hospital without any clinical evidence of intoxication but an elevated blood cyanide level. The authors explain this discrepancy with the following hypotheses: 1) the patient ingested cyanide as an iron-chelated complex; and 2) the sulfuric acid used in the standard microdiffusion technique released cyanide from its iron-bound state to result in the observed elevated blood cyanide. Through a series of in vitro analyses, the authors demonstrate the following: 1) the ingested solution tested positive for cyanide with the sulfuric acid technique and negative for cyanide with acetic acid; 2) the presence of a ferrous salt in the ingested product by a colorimetric redox titration technique; and 3) release of a small fraction of the total cyanide from ferrocyanide by the sulfuric acid technique. The authors conclude: 1) the patient ingested potassium ferrocyanide; and 2) the strong acid used in the cyanide microdiffusion assay will liberate cyanide that is chelated to iron to yield false positive results.

[Ecstasy and its "counterparts"]. / L'ecstasy et ses "sosies".

RISK AWARENESS: Use of psychostimulants is spreading in France, particularly at "techno" dances. The generic term "ecstasy" covers a wide variety of molecules with variable formulations. The situation is a true public health problem, generally concerning very young subjects who must be informed of the risks involved. Knowledge of the chemical makeup of the products currently used is needed to provide valid information and reduce risks. CHEMICAL ANALYSIS: Two types of chemical analysis are used for rapid controls. A coloration test is used by the Rave mission implemented by "Médecins du Monde". More elaborate analysis methods are used to identify the active substances and quantify the compounds in the different "tablets". FINDINGS: Rapid controls give a means of quickly identifying samples containing methylenedioxyamphetamines and distinguishing them from other samples which may contain any number of substances with unknown toxicity. A precise analysis of 73 samples has shown highly variable compositions with 22% actually containing methylenedioxyamphetamines. PREVENTION: Precise analytical knowledge of the drugs circulating in "techno" dances has revealed the extreme danger of a large number of the substances used. A continuous control of ongoing consumption is required to correctly warn the users and reduce risk.

[Determination of drugs for the diagnosis and the surveillance of acute poisoning]. / Dosage des médicaments pour le diagnostic et la surveillance des intoxications aiguës.

Acute drug poisonings are the first cause of hospital admission among in individuals less than 30 years of age in developed countries. In order to face this problem, an analytic process, including two steps, is proposed; first, a qualitative step leads quite quickly to a medical diagnosis; second, a quantitative step, in close collaboration with the clinician, allows a well adapted reanimation. The result is that the patient receive a quicker and more efficient treatment. Both the analyst and the clinician must know the limits and the requirements of such techniques.

[A case of lithiasis caused by 2,8 dihydroxyadenine. Evolutive characteristics. Therapeutic problems]. / Un cas de lithiase de 2.8.dihydroxyadénine. Particularités évolutives. Problèmes thèrapeutiques.

We report a case of bilateral 2,8 dihydroxyadenine urolithiasis in a 25-year-old woman, born from an incestuous union between a brother and sister, who developed the first manifestations at the age of 9 years. This condition results from APRTase deficiency and an autosomal recessive inherited disorder. Diagnosis requires physical analysis of the stones and measurement of APRT activity in red cells. Treatment by lithotripsy with piezo-electric shock waves was ineffective on the left leading to eventual nephrectomy. The right lithiasis was destroyed by lithotripsy. This result would suggest variable solidity of 2,8 dihydroxyadenine stones. In this patient, an indwelling endoprosthesis was left in place for 14 months for extra-medical reasons and led to staphylococcal urinary infections, struvite lithiasis and incrustations of the catheter within the bladder. Ureteroscopy and percutaneous nephrostomy were required to remove this secondary radio-opaque stone.

[Urinary calculi, consisting of dehydrated calcium phosphate. Clinical, biological, radiologic aspects, clinical course and management]. / Lithiase urinaire de brushite. Particularités cliniques, biologiques, radiologiques, évolutives et thérapeutiques.

Seventeen cases of urinary calculi analyzed by infrared spectrophotometry were found to be composed entirely or nearly entirely of bihydrated calcium hydrophosphate. The observations are summarized here. This type of stone occurs with a frequency of about 1% (0.85% in our experience) of all urinary calculi, predominantly in men (14 of our 17 cases). Diagnosis is based on the physical and chemical analysis of the stone and on infrared spectrophotometry. Most of these stones are pure or nearly pure compounds. The macroscopic aspect of the stones or fragments of stones can guide diagnosis. These stones are cream coloured stones with a smooth regular outer surface. Broken fragments show the same cream colour, sometimes with strips radiating from the centre of the fracture surface. Radiologically, these stones are homogeneously radio-opaque, often oval-shaped with a regular outline. Blood tests can demonstrate suspected or proven hyperparathyroidism (4 out of 10 cases in our 17 observations) with hypercalcemia, hypophosphatemia and hypercalciuria. Complementary examinations may be needed to search for a parathyroid adenoma. With or without hyperparathyroidism, 24-h urinalysis usually shows hypercalciuria up to ro over 500 to 600 mg/24 h. Crystallization usually occurs in the upper urinary tract, in the bladder or in indwelling catheters. These stones are extremely hard and are difficult to break in vitro. To be successful, lithotripsy requires prolonged treatment: up to 3000 to 6000 shockwaves at 22-23 kv with the Dornier apparatus. Despite the notion of hypercalciuria, the pathogenesis of bihydrated calcium hydrophosphate calculi remains to be elucidated.

[Uro-oxalic renal lithiasis. Certain characteristics]. / La lithiase rénale uro-oxalique. Quelques particularités.

In a paper published in 1974, it was reported that uro-oxalic stones are found more often in subjects with group O than with group A blood types although the proportions of these two blood types are approximately equivalent in the French population. The present work confirms these data, the ratio of group O to group A renal lithiasis being approximately 3 to 1. In a paper published in 1987, uro-oxalic stones were found to occur preferentially on the left side: 84 on the left and 39 on the right. The present work confirms this notion since in 57 cases, stones were bilateral in 2 cases, on the left in 39 and on the right in 16. Extra corporeal shock wave lithotripsy was performed in 40 of the 57 cases and showed that uro-oxalic stones are most resistant to shock-waves than the other types of stones. They are about as hard as calcium oxalate monohydrate stones or harder in certain cases: A mean of 3,865 shock-waves were required in the 40 cases of the uro-oxalic lithiasis treated with the HM3 Dornier device, while the mean number of shock-waves required for all types of stones in general varies from 2,000 to 2,500. In 4 cases, 5,000 or 6,000 high power shock-waves (7,000 in one session and 9,500 in two sessions) had to be used to obtain a satisfactory result. The calcium oxalate part of these stones is almost always composed of calcium oxalate monohydrate.(ABSTRACT TRUNCATED AT 250 WORDS)

Microassay of propranolol enantiomers and conjugates in human plasma and urine by high-performance liquid chromatography after chiral derivatization for pharmacokinetic study.

A microdetermination of propranolol enantiomers and of their glucuronide and sulphate conjugates in human plasma and urine by reversed-phase HPLC after chiral derivatization is described. After extraction from 100 microliters of plasma or urine with racemic 4-methylpropranolol as internal standard (I.S.), the enantiomers are derivatized with R(+)-phenylethylisocyanate as chiral derivatization reagent. Chromatography is performed on Novapak C18 column with fluorescence detection. Glucuronide and sulphate conjugates are cleaved prior to extraction by incubating, respectively, the samples with glucuronidase-arylsulphatase and saccharic acid 1-4 lactone as specific glucuronidase inhibitor. The retention times of propranolol and I.S. enantiomer derivatives are short (tR = 5.5-6.2 min and 8.8-10.1 min, respectively). The diastereomeric derivatives are very stable and show good peak symmetry and resolutions (RS = 2 and 2.2). The use of 4-methylpropranolol as I.S. improves significantly relative standard deviations (RSD: 1.7-5.1). Sensitivity is about 1 ng ml-1 per enantiomer. The method is applied to pharmacokinetic studies of racemic propranolol in human plasma and urine. S-propranolol and its conjugates show higher concentrations than R-propranolol and its conjugates in plasma and urine.

[Uro-oxalic renal lithiasis. Special aspects]. / La lithiase rénale uro-oxalique. Quelques particularités.

In a paper published in 1974, it was reported that uro-oxalic stones are found more often in subjects with group O than with group A blood types although the proportions of these two blood types are approximately equivalent in the French population. The present work confirms these data, the ratio of group O to group A renal lithiasis being approximately 3 to 1. In a paper published in 1987, uro-oxalic stones were found to occur preferentially on the left side: 84 on the left and 39 on the right. The present work confirms this notion since in 57 cases, stones were bilateral in 2 cases, on the left in 39 and on the right in 16. Extra corporeal shock wave lithotripsy was performed in 40 of the 57 cases and showed that uro-oxalic stones are more resistant to shock-waves than the other types of stones. They are about as hard as calcium oxalate monohydrate stones or harder in certain cases: A mean of 3,865 shock-waves were required in the 40 cases of the uro-oxalic lithiasis treated with the HM3 Dornier device, while the mean number of shock-waves required for all types of stones in general varies from 2,000 to 2,500. In 4 cases, 5,000 or 6,000 high power shock-waves (7,000 in one session and 9,500 in two sessions) had to be used to obtain a satisfactory result. The calcium oxalate part of these stones is almost always composed of calcium oxalate monohydrate.(ABSTRACT TRUNCATED AT 250 WORDS)

[A case of a large pyelic calculus composed only of ammonium urate]. / A propos d'un cas de gros calcul pyélique constitué uniquement d'urate d'ammonium.

The authors report a case of pure ammonium urate stone. It was a very large lightly radiopaque pelvic stone, which was extracted by pyelotomy and analysed by infra-red spectrography. The clinical history did not reveal a long history of chronic infections. The stone was diagnosed by urography performed after an acute urinary trad infection. Proteus mirabilis was found at one time, but only after the surgical operation. The blood and urinary laboratory check-up was normal. No case of such a large pure ammonium urate stone especially in adults, can be found in the literature. The pathogenesis is not obvious, and could not be explained without an abnormal urinary ammonia production during the development of the stone, but the lack of associated phosphate precipitation cannot be explained.

[Extracorporeal shockwave lithotripsy and cystine lithiasis. Our experience apropos of 11 cases]. / Lithotritie extracorporelle par ondes de choc et lithiase cystinique. Notre expérience à propos de onze cas.

The authors report their experience of the treatment of cystine lithiasis by ESWL on the basis of 11 cases from 1984 to 1987.

[Application of derivative spectrophotometry in biochemistry]. / Applications de la spectrophotométrie dérivée en biochimie.

Derivative spectrophotometry is used to increase the specificity of spectroscopic measurements. The main advantages of this method are a better resolution of overlapping bands and a reduction in the effects of turbidity and coloured background. Its biochemical applications of this method are reviewed.

[Not Available]. / Etude de la purete des echantillons commerciaux d'eosine.

Eight commercial samples of eosin have been analysed. Three problems were encountered in selecting material for use as a drug: the degree of hydration, the inorganic content and, above all, the composition of the xanthene moiety, which could contain up to 8 dyes.