Effectiveness of bacteriophages in the sputum of cystic fibrosis patients.

Bacteriophages have been shown to be effective for treating acute infections of the respiratory tract caused by antibiotic-resistant bacteria in animal models, but no evidence has yet been presented of their activity against pathogens in complex biological samples from chronically infected patients. We assessed the efficacy of a cocktail of ten bacteriophages infecting Pseudomonas aeruginosa following its addition to 58 sputum samples from cystic fibrosis (CF) patients collected at three different hospitals. Ten samples that did not contain P. aeruginosa were not analysed further. In the remaining 48 samples, the addition of bacteriophages led to a significant decrease in the levels of P. aeruginosa strains, as shown by comparison with controls, taking two variables (time and bacteriophages) into account (p = 0.024). In 45.8% of these samples, this decrease was accompanied by an increase in the number of bacteriophages. We also tested each of the ten bacteriophages individually against 20 colonies from each of these 48 samples and detected bacteriophage-susceptible bacteria in 64.6% of the samples. An analysis of the clinical data revealed no correlation between patient age, sex, duration of P. aeruginosa colonization, antibiotic treatment, FEV1 (forced expiratory volume in the first second) and the efficacy of bacteriophages. The demonstration that bacteriophages infect their bacterial hosts in the sputum environment, regardless of the clinical characteristics of the patients, represents a major step towards the development of bacteriophage therapy to treat chronic lung infections.

Fast liquid chromatography/tandem mass spectrometry determination of cannabinoids in micro volume blood samples after dabsyl derivatization.

Due to the non-polar nature and the absence of an ionizable group on the cannabinoids, the ionization efficiency in electrospray is low and leads to poor limits of detection (LOD). The reaction of chloride dabsyl with the phenolic OH group of cannabinoids results in a product containing a tertiary amine, which is easily protonated in positive electrospray mode and can significantly improve the cannabinoids LOD. A rapid, selective and sensitive LC/MS-MS method was developed for quantitative determination of Δ(9)-tetrahydrocannabinol (THC), 11-hydroxy-Δ(9)-tetrahydrocannabinol (11-OH-THC), 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol (THC-COOH), cannabinol (CBN) and cannabidiol (CBD), in micro volume blood samples following dabsyl derivatization to enhance signal intensity. The method comprised protein precipitation followed by derivatization with dabsyl chloride and subsequent analysis using liquid chromatography-tandem mass spectrometry (LC/MS-MS). Chromatographic separation was achieved using a 150 mm × 2.1 mm C18 analytical column maintained at 65°C and eluted with a gradient of water and acetonitrile, both containing 0.2% formic acid. The run time was 8 min. The assay was successfully validated using the approach based on the accuracy profile. Lower limits of quantification (LOQ) were 0.25 ng/mL for THC and THC-COOH, 0.30 ng/mL for 11-OH-THC, 0.40 ng/mL for CBN and 0.80 ng/mL for CBD. A comparative study of cannabinoids in blood and plasma, as determined by the developed LC/MS-MS method or the in-house GC/MS-MS technique, demonstrated an excellent correlation between the two methods. Dabsylation was also tested on-line with a spiral of peek tubing placed in the LC/MS-MS column heater at 65°C before the analytical column. The results obtained with on-line dabsyl derivatization were similar to those observed off-line.

[Workplace testing of drugs of abuse and psychotropic drugs]. / Exploration biologique des drogues illicites et des médicaments psychotropes en milieu professionnel.

In France, workplace testing of drugs of abuse and psychotropic drugs is rarely performed; meanwhile it is a major public health problem. Furthermore, France is the European country that has been associated with the highest increase of the use of drugs of abuse, particularly cannabis. So workplace biological screening of drugs of abuse and of psychotropic drugs exposure is of major concern. New analytical techniques have been developed during the last years. The authors will consider analytical screening of drugs of abuse and particularly the comparison of analytical techniques applied to urine and saliva. The advantages and the disadvantages of these two matrices will be considered. Urinary and blood quantification will be reviewed, but also the interest of hair testing to explore chronic exposure. The research of psychotropic drugs in biological fluids is also a part of this paper. New analytical trends are promising and complete analysis of these substances will be soon routinely possible in blood using a single spot test.

[Cystic fibrosis and other channelopathies]. / La mucoviscidose et autres canalopathies.

Mutations in cystic fibrosis transmembrane conductance regulator gene, CFTR, are responsible for cystic fibrosis, CF, a channelopathie. CFTR protein is a multifunctional protein with a main function of Cl(-) channel. CFTR is expressed in epithelia (upper airways, intestine, pancreas etc.). In the first part of this revue, we describe the main properties of CFTR underlying that it is not only a Cl(-) channel protein but also a multifunctional protein. We present a hypothesis which postulates that CFTR is a hub protein interacting with more than 140 proteins, and through these interactions regulates a number of functions which are abnormal in CF (ion transport, inflammation etc.). In the second part of the revue we briefly present a selection of other epithelial channelopathies due to mutations in genes of other Cl(-) or cation channels. Of note, these channels either interacts with CFTR or are considered as alternative channels in CF, and, as such, are targets for pharmacotherapies. We want to leave the reader with a message that to investigate channalopathies, to dissect the molecular mechanisms underlying channels'activity, allow not only to better understand basic mechanisms of channel regulation but in fine, to propose new targets for pharmacotherapies.

On-line liquid chromatography/tandem mass spectrometry simultaneous determination of opiates, cocainics and amphetamines in dried blood spots.

A novel approach has been developed for the illicit drugs quantitative determination using dried blood spots (DBS) on filter paper. The illicit drugs tested were opiates (morphine and its 3- and 6-glucuronide metabolites, codeine, 6-monoacetylmorphine), cocainics (ecgonine methylester, benzoylecgonine, cocaine, cocaethylene) and amphetamines (amphetamine, methamphetamine, MDA, MDMA, MDEA). The described method, requiring a small blood volume, is based on high performance liquid chromatography coupled to tandem mass spectrometry using on-line extraction. A Whatman card 903 was spotted with 30µL of whole blood and left overnight to dry at room temperature. A 3-mm diameter disk was removed using a manual punch, suspended in 150µL of water for 10min with ultrasonication, and then 100µL was injected in the on-line LC-MS/MS system. An Oasis HLB was used as an extraction column and a C18 Atlantis as an analytical column. The chromatographic cycle was performed with 20mM ammonium formate buffer (pH 2.8) (solvent A) and acetonitrile/solvent A (90:10, v/v) gradient in 16min. Detection was performed in positive electrospray ionization mode (ESI+) with a Quattro Micro (Waters). Recoveries of all analytes were up to 80%. DBS were stored in duplicate at 4°C and -20°C for up to 6 months. Illicit drugs seemed to be much more stabled at -20°C. Furthermore, it was tested whether analysis of DBS may be as reliable as that of whole blood investigating authentic samples; significant correlations were obtained. This DBS assay has potential as rapid, sensitive and inexpensive option for the illicit drugs determination in small blood volumes, which seems of great interest in suspected cases of driving under the influence of drugs.

Accidental potassium dichromate poisoning. Toxicokinetics of chromium by ICP-MS-CRC in biological fluids and in hair.

Intoxications by chromium (Cr) compounds are very life threatening and often lethal. After oral ingestion of 2 or 3g of hexavalent Cr (Cr(VI)), gastrointestinal injury, but also hepatic and renal failure, often occurs which each leads to a fatal outcome in most patients. Cellular toxicity is associated with mitochondrial and lysosomal injury by biologically Cr(VI) reactive intermediates and reactive oxygen species. After Cr(VI) has been absorbed, there is not much that can be done except to control the main complications as the treatment is only symptomatic. The biotransformation of Cr(VI) to Cr(III) reduces the toxicity because the trivalent form does not cross cellular membranes as rapidly. In fact, more than 80% of Cr(VI) is cleared in urine as Cr(III). We report the case of a 58-year-old male patient who was admitted to hospital after accidental oral ingestion of a 30 g/L potassium dichromate (the estimated amount of ingested Cr is about 3g). ICP-MS equipped with a collision/reaction cell (CRC) and validated methods were used to monitor plasma (P), red blood cells (RBCs), urine (U) and hair chromium. For urine the results were expressed per gram of creatinine. After 7 days in the intensive care unit, the patient was discharged without renal or liver failure. P, RBC and U were monitored during 49 days. During this period Cr decreased respectively from 2088 µg/L to 5 µg/L, 631 µg/L to 129 µg/L and 3512 µg/g to 10 µg/g. The half-life was much shorter in P than in RBC as the poison was more quickly cleared from the P than from the RBC, suggesting a cellular trapping of the metal. Hair was collected 2 months after the intoxication. We report a very rare case of survival after accidental Cr poisoning which has an extremely poor prognosis and usually leads to rapid death. For the first time, this toxicokinetic study highlights a sequestration of chromium in the RBC and probably in all the cells.

Online liquid chromatography-tandem mass spectrometry cyanide determination in blood.

An original liquid chromatography-tandem mass spectrometry (LC-MS-MS) method coupled to online extraction has been developed for cyanide determination in blood. A method involving fluorimetric detection after naphthalene-2,3-dicarboxyaldehyde (NDA) complexation by taurine in the presence of cyanide was previously described. Its performance was limited because of the absence of an internal standard (IS). Using cyanide isotope (13)C(15)N as IS allowed quantification in MS-MS. After the addition of (13)C(15)N, 25 µL of blood were diluted in water and deproteinized with methanol. Following derivatization with NDA and taurine for 10 min at 4°C, 100 µL was injected into the online LC-MS-MS system. An Oasis HLB was used as an extraction column, and a C18 Atlantis was the analytical column. The chromatographic cycle was performed with an ammonium formate (20 mM, pH 2.8) (solvent A) and acetonitrile/solvent A (90:10, v/v) gradient in 6 min. Detection was performed in negative electrospray ionization mode (ESI(-)) with a Quattro Micro. For quantification, transitions of derivatives formed with CN and (13)C(15)N were monitored, respectively, as follows: 299.3/191.3 and 301.3/193.3. The procedure was fully validated, linear from 26 to 2600 ng/mL with limit of detection of 10 ng/mL. This method, using a small blood sample, is not only simple, but also time saving. The specificity and sensitivity of LC-MS-MS coupled to online extraction and using (13)C(15)N as the IS make this method very suitable for cyanide determination in blood and could be useful in forensic toxicology.

[A new medical concept: the metallic profile]. / Le profil métallique : un nouveau concept médical.

Over the past decade great progress has been made in metals and metalloids analysis. This analysis is a basic stage in toxicity assessment and is indispensable in achieving a realistic evaluation of substance toxicity. A recently introduced technique, inductively coupled plasma mass spectrometry (ICP-MS) is progressively replacing atomic absorption. This analysis permits multi-elementary determinations, approximately 30 elements, with an optimal gain in sensitivity in many biological matrices: i.e. whole blood, plasma, urine, hair, nail, biopsy samples. Moreover, this method allows semiquantitative determination with an additional 30 supplementary elements, which enables the toxicologist to sufficiently estimate the toxic levels and metal exposure. The authors demonstrate that the ICP-MS could be very useful for a wide range of clinical applications. Furthermore, this procedure offers new exploration possibilities in various fields such as clinical toxicology, forensic toxicology as well as work place testing or environmental exposure and permits epidemiologic studies. This analytical method in fact also provides a new scientific approach. To our knowledge we are the first to propose: the metallic profile.

MRI gadolinium-based contrast agents. Radiologists beware!

Gadolinium (Gd) is used in contrast agents as it enhances magnetic resonance imaging (MRI) signals. To reduce Gd toxicity, it is chelated into linear or macrocyclic complexes. Eight Gd-containing contrast agents have been approved by the European Medicines Agency (EMEA) for use in MRI, and six by the US Food and Drug Administration. Stability depends upon its physicochemical properties. When renal function is normal, the Gd is quickly cleared from the body by the kidneys. For patients with chronic kidney disease, the elimination is greatly reduced and Gd may be released from its chelate and deposit in body tissues, leading to nephrogenic systemic fibrosis (NSF). More than 200 cases of NSF have been reported in the world. NSF is characterized by an extensive fibrosis of skin and tissues, a very severe affection with possible lethal outcome. We propose recommendations to avoid the risk of NSF.

Application of inductively coupled plasma mass spectrometry multielement analysis in fingernail and toenail as a biomarker of metal exposure.

The application of inductively coupled plasma mass spectrometry (ICP-MS) to multielement analysis in fingernail and toenail as biological indices for metal exposure is presented. The ICP-MS measurements were performed using a Thermo Elemental X7CCT series. Fingernail specimens were obtained from 130 healthy volunteers, and paired fingernail and toenail samples from 50 additional healthy volunteers of both sexes were collected as well. After warm water and acetone decontamination, 20 mg fingernails and toenails were acid mineralized after a decontamination procedure, and 32-34 elements were simultaneously quantified after acid dilution following water calibration. Li, Be, B, Al, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Sr, Mo, Pd, Ag, Cd, Sn, Sb, Te, Ba, La, Gd, W, Pt, Hg, Tl, Pb, Bi, and U could be validated in fingernail and toenail samples. Linearity was excellent, and the correlation coefficients were above 0.999. Quantification limits ranged from 0.04 pg/mg or ng/g (U) to 0.1 ng/mg or microg/g (B). Because of the lack of available certified nail reference material, an adequate quality assessment scheme was ensured by comparison with an interlaboratory nail-testing procedure, and the results showed optimal consistency for elements tested. Results are presented and compared with published multielement data. Six cases of domestic exposure to lead were diagnosed based on fingernail analysis. Application of ICP-MS multielement analysis in fingernail and toenail as a biomarker of metal and nonmetal exposure permits greater noninvasive control of industrial, domestic, or environmental exposure and is very useful for epidemiological studies.

[Delta-9-tetrahydrocannabinol pharmacokinetics]. / Pharmacocinétique du delta-9-tétrahydrocannabinol (THC).

Delta-9-tetrahydrocannabinol (Delta-9-THC) is the main psychoactive ingredient of cannabis. Smoking is currently most common use of cannabis. The present review focuses on the pharmacokinetics of THC. The variability of THC in plant material which has significantly increased in recent years leads to variability in tissue THC levels from smoking, which is, in itself, a highly individual process. This variability of THC content has an important impact on drug pharmacokinetics and pharmacology. After smoking THC bioavailability averages 30%. With a 3.55% THC cigarette, a peak plasma level near 160 ng/mL occurs approximately 10 min after inhalation. THC is eliminated quickly from plasma in a multiphasic manner and is widely distributed to tissues, which is responsible for its pharmacologic effects. Body fat then serves as a long-term storage site. This particular pharmacokinetics explains the noncorrelation between THC blood level and clinical effects as is observed for ethanol. A major active 11-hydroxy metabolite is formed after both inhalation and oral dosing (20 and 100% of parent, respectively). The elimination of THC and its many metabolites, mainly THC-COOH, occurs via the feces and urine for several weeks. Thus, to confirm abstinence, urine THC-COOH analysis would be a useful tool. A positive result could be checked by gas chromatography-mass spectrometry THC blood analysis, indicative of a recent cannabis exposure.

Hair and fingernail gadolinium ICP-MS contents in an overdose case associated with nephrogenic systemic fibrosis.

Nephrogenic systemic fibrosis (NSF) is a rare acquired disorder affecting renal insufficiency patients. There is a growing recognition of the association between the rapid rise in the use of gadolinium (Gd)-containing contrast agents for magnetic resonance imaging (MRI), and the occurrence of acute nephrogenic systemic fibrosis. This case report concerns a 62-year-old woman with chronic renal insufficiency who underwent numerous MRI examinations using Gd-based contrast agents. For the first time, to our knowledge, Gd was performed in the NSF patient's blood, as well as in hair and in fingernails by inductively plasma coupled mass spectrometry. Gd contents in blood, hair and in fingernails were initially 300 to 1000 times higher compared to controls. These results are a new illustration of the strong association between the frequent use of Gd-based contrast media and NSF in patients with kidney diseases. Gd quantitative determination could be of major interest for patients with renal failure who are required to undergo repeated gadolinium-enhanced MRI examinations.