Development and validation of a HPLC-ES-MS/MS method for the determination of glucosamine in human synovial fluid.

A new HPLC method for the determination of glucosamine (2-amino-2-deoxy-D-glucose) in human synovial fluid was developed and validated. Synovial fluid samples were analyzed after a simple protein precipitation step with trichloroacetic acid using a polymer-based amino column with a mobile phase composed of 10 mM ammonium acetate (pH 7.5)-acetonitrile (20:80, v/v) at 0.3 mL/min flow rate. D-[1-13C]glucosamine was used as internal standard. Selective detection was performed by tandem mass spectrometry with electrospray source, operating in positive ionization mode and in multiple reaction monitoring acquisition (m/z 180-->72 and 181-->73 for glucosamine and internal standard, respectively). The limit of quantification (injected volume=3 microL) was 0.02 ng, corresponding to 10 ng/mL in synovial fluid. Calibration curves obtained using matrix-matched calibration standards and internal standard at 600 ng/mL were linear up to 2000 ng/mL. Precision values (%R.S.D.) were < or = 14% in the entire analytical range. Accuracy (%bias) ranged from -11% to 10%. The recoveries measured at three concentration levels (50, 800, and 1500 ng/mL) were higher than 89%. The method was successfully applied to measure endogenous glucosamine levels in synovial fluid samples collected from patients with knee osteoarthritis and glucosamine levels after oral administration of glucosamine sulfate (DONA) at the dose of 1500 mg/day for 14 consecutive days (steady-state).

[Membrane platelet fatty acids: biochemical characterisation of the ischemic cardiovascular disease, characteristics of the paediatric age, through an artificial neural network interpretation]. / Acidi grassi di membrana delle piastrine: tipizzazione biochimica della cardiopatia vascolare ischemica e caratteristiche dell'età pediatrica nell'interpretazione di una Rete Neurale Artificiale.

During the last 30 years, a huge research has been performed about the markers involved in the atherogenetic process and in the fatty acid thrombogenetic effect. More recently many studies have been made on the biochemical aspects of the saturated fatty acids with respect to the cardiovascular risk, in particular, the Stearic Acid (SA). Because of the peculiar characteristic of the platelets in the control of the thrombogenetic risk, we have investigated the platelet fatty acid profile in three groups of subjects: supposed healthy (n = 60), ischemic (n = 50), young children (n = 118). The aim of the study was to understand wich of the fatty acids could be evaluated as markers of the ischemic cardiovascular pathology and to have the possibility to classifie the subjects using the artificial neural network (ANN) system. The results highlight the peculiar position of the Oleic Acid, Linoleic Acid and Arachidonic Acid. According to the ANN results of the ischemic subjects, the young children were in the same position. Because this result is not commonly accepted, as children are healty, we have looked for a reason. There are well strong reasons to believe that all this is due to the stearic acid wich is extremely higher than the stearic acid of all the other subjects investigated. Particularly it has been underlined the possibility to modify the platelet stearic and oleic acid to obtain a better saturation index (Stearic/Oleic ratio). This could bring to a better control of the cardiovascular risk. It is possible, according with the results obtained, to open a new field of research on the lipid metabolism of the young children in relation to the atherogenesis. It is the first time that an observation on the platelet membrane phospholipid stearic acid is made in comparison to other adult subjects and a plausible explanation is given about the protection of the young children against the cardiovascular disease.

Impaired oxidative metabolism in exercising muscle from ALS patients.

The pathogenic mechanism of selective loss of motor neurones in amyotrophic lateral sclerosis (ALS) is still poorly understood. Recently, research evidence has suggested that mitochondrial dysfunction occurs in central nervous system as well as in peripheral tissues from ALS patients. The aim of our study was to indirectly investigate in vivo oxidative metabolism of exercising muscle in a case history of patients affected by ALS. To this purpose 11 patients, 8 male and 3 female, mean age+/-SD: 52.4+/-11.1 years, performed a bicycle incremental test for the assessment of lactate production. At rest, there was increased lactate concentration in patients: 2.77+/-0.79 vs. 1.48+/-0.49 mmol/l in normal controls (normal range: 0.67-2.47 mmol/l). Analysis of lactate curve during exercise showed a lactate production increase compared to controls. Furthermore, anaerobic lactate threshold was detected at 40-50% of the predicted normal power output, anticipated with respect to both normal subjects and non-ALS chronically denervated controls with comparable motor impairment (60-70%), suggesting that mitochondrial dysfunction can occur in exercising skeletal muscle from ALS patients.

Cortical silent period in patients with amyotrophic lateral sclerosis.

Transcranial magnetic stimulation (TMS) during a muscle contraction induces a motor-evoked potential (MEP) in the skeletal muscle followed by a cessation of EMG activity, the cortical silent period (C-SP). The C-SP is a useful parameter to indicate the activation of the motor system. Accurate determination of the C-SP can be important in amyotrophic lateral sclerosis (ALS), a progressive disorder of unknown etiology characterised by degeneration of upper and lower motor neurons. The aim of this study was to evaluate the sensitivity of C-SP as an index of motor system involvement, in ten patients affected by ALS, with a mean duration of the disease: 5. 5+/-3.4 months, by means of an objective computer-aided method to measure C-SP and its relationship to stimulation intensity. C-SP duration was significantly reduced in ALS patients compared to controls at low stimulation intensity corresponding to an MEP threshold increased by 15%. While in less severely affected patients C-SP duration approached control values at higher stimulation intensities (25 and 50% upper MEP threshold), in more severe ALS subjects it showed a further reduction, allowing them to be discriminated.

[Bacteria isolated in 1994-1995 in female upper genitalia infections and in male urethritis. Distribution and sensitivity to antibiotics]. / Bactéries isolées en 1994-1995 au cours des infections gynécologiques hautes et des uréthrites masculines. Distribution et sensibilité aux antibiotiques.

OBJECTIVE: Classify antibiotics according to their individual activity so as to identify those suitable for empiric therapy. METHODS: We studied bacterial strains isolated from patients with urethritis (n = 189) and upper genital tract infections (n = 163) between June 1994 and February 1995 in 3 hospital and 4 community laboratories. Upper genital tract infections were divided into two groups: proven infection on laparoscopy specimen (n = 79) and suspected infection with isolation of pathogen in cervical samples (n = 84). Pathogens isolated were: Chlamydia trachomatis in 36/12/15 cases respectively, Mycoplasma hominis in 12/20/13, Ureaplasma urealyticum in 55/30/15, Neisseria gonorrhoeae in 40/2/0, Haemophilus spp in 20/2/1, group B streptococci in 7/1/8, E. coli in 8/1/17 and miscellaneous in 11/8/15. The minimal inhibitory concentrations for all strains were determined in 4 laboratories for ofloxacin, erythromycin and doxycyclin against C. trachomatis, M. hominis and U. urealyticum, and for ofloxacin, erythromycin, doxycyclin, amoxicillin+clavulanate, cefotaxime and gentamicin against the other strains. The activity score (% susceptibility to each antibiotic weighted by the frequencies of each isolate in urethritis and upper genital tract infection based on recent French epidemiologic data) was calculated for each antibiotic. CONCLUSION: The antibiotics with the best empiric activity scores in urethritis were, in decreasing order: doxycyclin (90.4%), ofloxacin (88.1%), and erythromycin (50.2%). The most active combinations in upper genital tract infections were ofloxacin+amoxicillin (100%), doxycyclin+cefotaxime+metronidazole (95.9%) and doxycyclin+amoxicillin (95.3%).

[Gynecologic infections and sterility]. / Infections gynécologiques et stérilité.

The authors consider all the mechanisms through which a genital infection is able to affect fertility and fecundity. They conclude that a strict diagnosis and treatment must complement accurate information of the public by physicians.

[The role of Chlamydia trachomatis in producing abnormal movements by spermatozoa]. / Le rôle de Chlamydia trachomatis dans la survenue de mouvements anormaux des spermatozoïdes.

The authors analysed 100 sperm samples from asymptomatic patients and compared them with a control series of sperm donors who had been considered fertile by CECOS of Marseille or from men whose partners had conceived. They found Chlamydia trachomatis in 29% of the cases studied (P less than 0.0001). They found an abnormal movement of the sperm which they called the "Jerk Phenomenon" and which was found in 76% of cases (P less than 0.0001), where the culture for Chlamydia trachomatis was positive. This correlation does not change in association with other germs. Micro-cinematographic studies confirm the asthenospermic character of this movement. Since the sperm movements become normal after treatment with tetracycline one must consider that Chlamydia trachomatis can be an etiological agent for infertility in men.

[Role of Chlamydia trachomatis in male urethritis. Analysis of 2,000 cases of male urethritis]. / Place de Chlamydia trachomatis dans les uréthrites masculines. Analyse de 2,000 cas d'uréthrites masculines.

A study involving of 2,000 cases of urethritis revealed the presence of Chlamydia trachomatis in 44% of patients. Following a pathophysiological review, the strongly suggestive clinical picture of infection by this microorganism is emphasized. This study stresses two precise points by dealing with: firstly, the importance of the choice of technique for demonstration of the presence of the bacteria, and its reliability; secondly, the value of bacteriological evidence of the infection in order to treat not only the patient but also the partner(s) and to subsequently confirm the treatment as being effective.