Measurement of carbon monoxide in simulated expired breath.

BACKGROUND: Environmental carbon dioxide (CO) detectors used as an early warning method have been adapted to measure CO concentration in expired breath. This technique has been validated in smokers with relatively low CO concentrations, but its applicability to poisoning has not been demonstrated. OBJECTIVE: To compare the reliability of toxicologically significant CO measurements performed using a portable CO detector with those obtained using infrared spectrometry, the standard method for blood CO concentration determination. DESIGN: Experimental study with a CO detector and infrared spectrometer. A balloon simulated respiratory movements and an expired breath. Balloon gas mixtures contained CO, in one of 21 different concentrations from 100 to 600 parts per million (ppm) in air. CO concentration was measured directly with the portable CO detector and two gas samples obtained at the beginning and end of the simulated expired breath were diluted, with validation, for spectrometric measures. MAIN OUTCOME MEASURES: Portable CO detector concentrations were compared with the mean value of the reference method. Simple linear regression was performed using ANOVA to evaluate the parallel between the model with the reference method. RESULTS: Portable CO detector concentration measurements were perfectly linear (R2=0.989, P<10(-3)) over a concentration range of 46-645 ppm. The difference from the reference plot was significant (P<0.01). CONCLUSION: Given the linearity of the measurements, the underestimation by the portable CO detector at higher concentrations can be corrected mathematically. A portable CO detector should measure CO in expired breath efficiently and reliably.

Therapeutic trial of diazepam versus placebo in acute chloroquine intoxications of moderate gravity.

OBJECTIVE: Acute chloroquine intoxication is responsible for a membrane-stabilising effect which results in electrocardiographic (ECG) and hemodynamic disturbances. Diazepam is used in acute chloroquine intoxication on the basis of clinical and experimental observations, but its utility alone, in man, remains unproven. The goal of this study was to verify whether diazepam alone has an effect on the membrane-stabilising effect observed in moderately severe chloroquine intoxications. DESIGN: Prospective, multi-center, double-blind, placebo-controlled study. SETTING: Prehospital mobile intensive care units (Paris) and hospital intensive care units (paris and Dakar). PATIENTS AND PARTICIPANTS: Adults with moderately severe intoxication defined as: a suspected ingested dose of 2 or more but less than 4 g, systolic blood pressure (SBP) higher than 80 mmHg, QRS duration less than 0.12 s and the absence of dysrhythmia at inclusion. INTERVENTIONS: Patients received either a loading dose of 0.5 mg/kg diazepam followed by an infusion of 1 mg/kg over 24 h or an equivalent volume of placebo. MEASUREMENTS AND RESULTS: Outcome was measured by serial assessments of SBP, ECG (QRS and QT segments) and clinical deterioration. There were no significant differences observed in the initial or serial ECG or SBP measurements. There were no deaths and no patient had to be removed from the study due to clinical deterioration. CONCLUSIONS: Diazepam, at the dose studied, does not appear to reverse the chloroquine-induced membrane-stabilising effect in acute moderately severe chloroquine intoxication. Supportive intensive care of these intoxications appears to be all that is necessary.

Spectrophotometric determination of plasma thiocyanate by formation of an ion-pair with methylene blue.

We describe a sensitive method for measuring thiocyanate in 500 microliters plasma samples. This technique, although slower than the standard method, improves sensitivity. It requires the extraction in chloroform of an ion-pair formed between thiocyanate ions and methylene blue in acidic medium. Within-day precision had a coefficient of variation of 2.5% and between-day precision a CV of 4.75%. The results were well-correlated (r = 0.997). For 30 non-smokers, the mean thiocyanate level was < 55 mumol/l, and for 30 smokers 90 mumol/l (SD = 20). The method was successfully applied to seven fire smoke victims treated with hydroxocobalamin.

[Intraperitoneal chemotherapy for ovarian adenocarcinoma: pharmacokinetics of cisplatin]. / Chimiothérapie intrapéritonéale pour adénocarcinome ovarien: pharmacocinétique du cisplatine.

Chemotherapy using cis dichlorodiamine platinum (CDDP) in doses of 30 and 60 mg/m2 was carried out in 6 patients who had adenocarcinoma of the ovary, that had not been treated before, 15 to 120 minutes before surgery was carried out. The results of doses of platin given on the blood levels are demonstrated. A slight and progressive increase in the plasma levels of CDDP with peaks between 0.6 and 1.95 of total platinum and 0.22 mcg/ml of free platin were found. The tissue levels in the region of the ovaries were found to be between 0.16 and 0.94 mcg/mg. There was a stepwise increase in the levels found in the pathological peritoneal cover of between 0.42 and 31.2 mcg/mg. This dropped as time went by; and then led to change in accordance with the intra-peritoneal concentrations. This study shows that it is possible when giving drugs intraperitoneally to avoid high plasma peaks and to obtain good levels of concentration of cisplatin in the peritoneum.

[Analytical exploration of drug addiction]. / Exploration analytique des toxicomanies.

The natural and synthetic substances most frequently leading to drug addiction are described. They include cannabis, opium and cocaine with their respective derivatives. The authors insist on the problems encountered by analytical chemists when they examine urine samples containing these substances, owing to their metabolic degradation and to interferences between lawful and unlawful drugs. The limitations imposed by these problems to an unambiguous interpretation of the results obtained are defined, but they do not throw any doubt on the value of these investigations.

Aluminium loading in children receiving long-term parenteral nutrition.

Eight children on long-term, total parenteral nutrition (TPN) were found to have elevated aluminium (Al) levels in plasma (51 +/- 11 microg 1/1), urine (223 +/- 78 microg 24 h) and bone. The load of Al in TPN solution was 232 +/- 89 microg/day, and, among the different parenteral solution components high Al concentrations were found in amino-acids, calcium gluconate, potassium lactate, and trace elements, representing respectively 40%, 30%, 15%, and 10% of the total Al intakes. The authors conclude that children receiving long-term TPN have excessive Al intakes and are exposed to Al toxicity. The prevention of Al contamination requires careful control of the TPN components.

[The importance of software for the planning and adjusting of dosage. Application with aminoglycosides]. / Intérêt d'un logiciel informatique pour la prévision et l'adaptation des posologies. Application aux aminosides.

We are presenting a Mac Intosh--Apple computer program (Excel*) for the aminoglycosides (AG) drug monitoring useful in the following situations: --initiation of an AG's dosing regimen depending on the desired peak and through concentration (AG's pharmacokinetic parameters have been calculated according to the AG's literature values). --an adequate dosing regimen after revision of the patient's parameters (calculated with the observed concentrations). The technique has been validated comparing desired (des. C) and measured concentrations (mes. C). --either at the beginning of the treatment, --or after revision of the individual parameters. In the first case, the correlation coefficient obtained between 14 des C and 14 mes. C is equal to 0.91 and is improved when individual parameters are calculated (0.94).

[Malaria in Guiana. I. General status of the endemic]. / Le paludisme en Guyane. I. Situation générale de l'endémie.

Before 1949 malaria was highly prevalent in the whole territory of French Guiana. When malaria control based on house-spraying and drug prophylaxis was implemented in 1950 the disease sharply dropped below 20 cases per year. Since 1976 despite vector control malaria is rising again. In 1987, 3,269 cases have been notified giving an incidence of 37.6 per thousand for the whole country population; only four deaths were recorded. All the age groups were concerned but the transmission was restricted to some foci along the Oyapock river (prevalence rate 25%), along the Maroni river (prevalence 2.3%) and in a few places of the coastal area. The main cities remain malaria free. In vivo resistance to chloroquine was observed in 22% of the cases which could be cleared by amodiaquine or quinine.

[Malaria in Guiana. II. The characteristics of different foci and antimalarial control]. / Le paludisme en Guyane. II. Les caractéristiques des différents foyers et la lutte antipaludique.

In French Guiana, the distribution of malaria in foci inhabited by quite different ethnic groups calls for specific studies. Along the Oyapock on the Brasilian border and along the Litani on the Surinam border, incidence among American Indians and Creoles ranges from 300 and 900 per thousand; Plasmodium falciparum accounts for 65% and P. vivax for 35%. Along the middle and lower Maroni on the Surinam border, the Boni and Ndjukas Negroes move freely through the frontier and since the civil strife Surinamese used to attend health centres of Guiana. Therefore it is difficult to find the sources of contamination and the incidence among French citizens; P. falciparum is the only parasite recorded in this focus. In 1987 a small outbreak mainly due to P. vivax, occurred in a Lao refugees village in the hinterland. The coastal foci harbour large communities of Haitian and Brazilian migrants. The vector is Anopheles darlingi and up to now there is no evidence that other species could be involved. The rise of malaria despite of control measures involves several factors: the house spraying is no more accepted by a large percentage of house holders and the alternative larviciding has only a limited efficacy; the houses of American Indians have no walls to be sprayed; there is a continuous introduction of parasites by migrants. It has been said that vectors have change their behaviour toward exophily but such a statement has not yet been supported by evidence. All these factors should be taken in account to improve malaria control.

Protective cardiovascular effects of diazepam in experimental acute chloroquine poisoning.

To assess the effects of diazepam in chloroquine poisoning, we studied pentobarbital anesthetized and mechanically ventilated pigs. All the pigs received 50 mg.kg-1 chloroquine given intravenously for 25 min. Eight pigs acted as control (group C). Another 7 were treated with diazepam given intravenously 5 min after the end of chloroquine infusion: 2 mg.kg-1 of diazepam for 2 min, then 1 mg.kg.h-1 for 25 min (group D). Thereafter, all pigs were sacrificed. In both groups the chloroquine infusion induced a large fall in arterial pressure, a decrease in heart rate, and an increase in QRS duration. No difference was observed between the 2 groups for weight, systolic and diastolic arterial pressures, heart rate, QRS and QT durations before diazepam. After diazepam, systolic and diastolic arterial pressures, heart rate, urine volume, urinary excretion of chloroquine, plasma and blood cell chloroquine levels were higher, whereas QRS duration was lower, in group D compared to group C. No difference was observed between the 2 groups for urinary concentration of chloroquine, the ratio between plasma and blood cell chloroquine levels, hepatic, cardiac, and skeletal muscle chloroquine levels, and QT duration. After diazepam, the slope of the regression curve between QRS duration and plasma chloroquine levels was reversed in group D compared to group C. We conclude that diazepam counteracts some haemodynamic and electrocardiographic changes, and increases urinary excretion of chloroquine, in acute experimental chloroquine poisoning.

[Intracorporeal concealment of narcotics. Experience of medicolegal emergencies at the Hôtel-Dieu Hospital in Paris: 100 cases]. / Dissimulation intracorporelle de stupéfiants. Expérience des urgences médico-judiciaires de l'Hotel-Dieu de Paris: 100 cas.

One hundred cases of intracorporeal concealment of narcotic drugs were observed over a 6-month period at the medico-judicial emergency centre of the Hotel-Dieu hospital, Paris. Twelve cases concerned dealers who had ingested packs at the time they were arrested. The other subjects had been carrying the drug in their digestive tract, rectum or vagina for transportation. The illicit drugs thus transported were cocaine in 20 cases (ingestion), heroin in 65 cases (ingestion 7, rectal or vaginal cavity 58) and cannabis in 3 cases. Packs for sale being fragile, the dealers were particularly exposed to overdosage. Their management prior to intoxication was the same as that of acute ordinary drug poisoning, i.e. washing out of the stomach. In carriers, the risk of severe poisoning was associated with ingestion. The lack of antidote makes cocaine poisoning particularly dangerous. Surgical extraction is now reserved to cases with intestinal mechanical complications and to those increasingly rarer cases of fragile transportation packs.

Occurrence of manganese, copper and zinc in myelin. Alterations in the peripheral nervous system of dysmyelinating trembler mutant are at variance with brain mutants (quaking and shiverer).

Mn, Cu and Zn were present in mouse brain at concentrations that were 54, 4 and 14 times higher than in serum. In comparison with control animals, Mn was nearly normal in both quaking and shiverer dysmyelinating mutants. Cu was slightly higher in shiverer; Zn was higher in quaking only when expressed on a dry weight basis. The peripheral nervous system contained lower amounts of Mn, Cu and Zn than brain, (1 6 , 1 8 and 1 2 respectively). All three metals were much higher in trembler (4, 3 and 2-fold increase, respectively). Although higher in shiverer and quaking, Mn did not differ significantly from control. Cu and Zn were similar to control in the sciatic nerve of quaking and shiverer. Brain myelin contained Mn, Cu and Zn concentrations that were slightly smaller than those found in the whole brain. Mn and Cu were higher in the myelin from shiverer by approx. 2- and 3-times, whereas Zn was two-fold reduced. It is speculated that such metals play a role in membrane as cofactors of enzymes, especially those in control of free radical damage, and possibly also in membrane structures as phospholipid counterions.

Arterial-venous plasma concentration differences of meprobamate in acute human poisonings.

Arterial-venous plasma concentration differences of meprobamate were studied on admission of acute overdose in man. The patients were divided in two groups. In the control group (n = 25) two successive blood samples were collected from the same vessel. In the study group (n = 35) femoral arterial and venous blood samples were collected simultaneously. In the control group the differences were not significant. In the study group the differences were statistically significant (P less than 0.01). The present study suggests that the origin of blood samples should be stated for toxicological studies and that the toxicokinetics may be more complex than those recognized previously.

[Guidelines for prescription of the assay of digitalis glycosides by immunologic methods]. / Règles de prescription du dosage des digitaliques par méthodes immunologiques.

Digoxin, digitoxin and acetyldigitoxin are the most widely prescribed of cardiotonic glycosides. Analytical exploration can be performed by a single assay when only one compound is prescribed or by multiple assays in cases of imprecise prescription or when several glycosides are given concomitantly. In addition, the metabolic transformation of digitoxin into digoxin and the presence of endogenous "digitalis-like compounds" mean that a number of precautions must be taken during prescription. These examples underline the ambiguity of the so-called "digitalinaemia" prescriptions and the need for biologists to be supplied with maximum information by clinicians.