[Prevalence in Mexico of giant cell tumor, osteosarcoma and chondrosarcoma (2013-2017)]. / Prevalencia en México del tumor de células gigantes, osteosarcoma y condrosarcoma (2013-2017).

INTRODUCTION: Primary bone tumors make up 1% of cancers in adults, the most common being osteosarcoma and chondrosarcoma. Giant cell tumor (GCT) is a locally aggressive benign neoplasm, accounting for 4-10% of all primary bone tumors, but in certain populations it accounts for up to 20%. The main objective of this work was to determine the proportion of GCTs, osteosarcomas and chondrosarcomas in a period of five years, and describe the characteristics of the patients from whom they come. Clinical implications: More information about the epidemiology of bone tumors is required to know their epidemiology in the Mexican population. MATERIAL AND METHODS: Descriptive observational study of a retrospective cross section including all patients who underwent surgery for tumoral resection, in public hospitals at national level, and whose histopathological pieces were processed and resulted in tissue compatible with a) GCT, b) osteosarcomas and c) chondrosarcomas. RESULTS: Between 2013 and 2017, 138 cases of the three primary bone tumors studied were reported, giant cell tumor (50%), osteosarcoma (25.36%) and chondrosarcoma (24.64%). The states with the highest number of cases were the state of Mexico (45.65%) and Mexico City (26.81%). Women had a higher prevalence (57.25%) than men (42.75%). The average age of presentation of the tumors was 36.80 years. CONCLUSIONS: GCT is not an uncommon tumor in the Mexican population, since it has its own characteristics.

INTRODUCCIÓN: Los tumores óseos primarios constituyen 1% de los cánceres en el adulto, siendo los más frecuentes el osteosarcoma y el condrosarcoma. La tumoración de células gigantes (TCG) es una neoplasia benigna localmente agresiva, que representa de 4-10% de todos los tumores óseos primarios, pero en ciertas poblaciones representa el hasta 20%. El objetivo principal de este trabajo fue determinar la proporción de los TCG, osteosarcomas y condrosarcomas en un período de cinco años y describir las características de las pacientes de los cuales proceden. Importancia clínica: se requieren más datos acerca de la epidemiología de los tumores de los huesos, para conocer su epidemiología en la población mexicana. MATERIAL Y MÉTODOS: Estudio observacional descriptivo de corte transversal retrospectivo incluyendo a la totalidad de pacientes que fueron intervenidos quirúrgicamente mediante resección tumoral, en los hospitales públicos a nivel nacional, y cuyas piezas histopatológicas fueron procesadas y dieron como resultado tejido compatible con: a) TCG, b) osteosarcomas y c) condrosarcomas. RESULTADOS: Entre el 2013 y 2017 se reportaron 138 casos de los tres tumores óseos primarios estudiados, el tumor de células gigantes (50%), el osteosarcoma (25.36%) y el condrosarcoma (24.64%). Los estados que tuvieron mayor número de incidencias fueron el Estado de México (45.65%) y la Ciudad de México (26.81%). Las mujeres presentaron una mayor prevalencia (57.25%) que los hombres (42.75%). La edad media de presentación de los tumores fue 36.80 años. CONCLUSIONES: El TCG no es una tumoración infrecuente en la población mexicana, ya que cuenta con características propias.

Influence of oxidative homeostasis on bacterial density and cost of infection in Drosophila-Wolbachia symbioses.

The evolution of symbioses along the continuum between parasitism and mutualism can be influenced by the oxidative homeostasis, that is the balance between reactive oxygen species (ROS) and antioxidant molecules. Indeed, ROS can contribute to the host immune defence to regulate symbiont populations, but are also toxic. This interplay between ROS and symbiosis is notably exemplified by recent results in arthropod-Wolbachia interactions. Wolbachia are symbiotic bacteria involved in a wide range of interactions with their arthropods hosts, from facultative, parasitic associations to obligatory, mutualistic ones. In this study, we used Drosophila-Wolbachia associations to determine whether the oxidative homeostasis plays a role in explaining the differences between phenotypically distinct arthropod-Wolbachia symbioses. We used Drosophila lines with different Wolbachia infections and measured the effects of pro-oxidant (paraquat) and antioxidant (glutathione) treatments on the Wolbachia density and the host survival. We show that experimental manipulations of the oxidative homeostasis can reduce the cost of the infection through its effect on Wolbachia density. We discuss the implication of this result from an evolutionary perspective and argue that the oxidative homeostasis could underlie the evolution of tolerance and dependence on Wolbachia.

[A case of fatal cocaine overdose]. / Intoxication mortelle à la cocaïne.

Clinical, biological, and therapeutic description of a lethal case of cocaine overdose.

[Multicenter evaluation of h-FABP semi-quantitative assay (Cardio Detect) in central laboratory: the point in acute myocardial infarction diagnosis]. / Evaluation multicentrique du dosage semi-quantitatif de la h-FABP (Cardio Detect) au laboratoire central : intérêt dans le diagnostic de l'infarctus du myocarde.

The diagnostic performance of heart-Fatty Acid Binding Protein (h-FABP) (semi-quantitative CardioDetect test) and cardiac troponin I (TnIc) blood assays were compared in one hundred patients presenting with suspicion of acute coronary syndrome. Final patient diagnosis was "acute myocardial infarction" in 36 cases, "non ST myocardial infarction" in 25 cases and "non ischemic pathologies" in 39 cases. h-FABP results were positive in 26 patients, negative in 57 patients and ambiguous in 17 patients, the latter corresponding to the final diagnosis of "acute myocardial infarction" in 5 cases, "non ST myocardial infarction" in 2 cases and "non ischemic pathologies " in 10 cases. At admission, h-FABP and TnIc exhibiteda sensitivity of 54% an 66%, respectively and a specificity of 86% and 95%, respectively. Positive and negative predictive values were 81% and 64% for h-FABP, respectively and 92% and 75% for cTnI, respectively. h-FABP and cTnI demonstrated a similar diagnostic efficiency if admission delay is less than 4 hours after onset of chest pain (area under ROC curve TnIc = 0.767 +/- 0.091 ; area under ROC curve h-FABP = 0.622 +/- 0.109 ; p = 0.144). On the contrary, cTnI assay demonstrated a better efficiency than h-FABP (p< 0.005) for patients admitted in a delay of 4 to 12 hours after the onset of chest pain. If chosen cTnI cut-off corresponded to the recent consensus definition used for monitoring acute coronary syndrome patients, h-FABP semi-quantitative assay realized within central laboratory did not demonstrated a better diagnostic efficiency than cTnI.

[Adaptation of methotrexate determination in plasma with Dimension Xpand]. / Adaptation du dosage plasmatique du méthotrexate sur Dimension Xpand.

The treatment with methotrexate at high doses is responsible of many side effects. It's necessary to evaluate serum methotrexate rate to monitor the administration of the methotrexate antagonist, the folinic acid. The aim of this study is to validate the determination of methotrexate in plasma using the automate Xpand Dimension (Dade Behring). Assay results were linearly related to the concentration for the wide range which was examinated (0.15 - 1.4 micromol/L). We report the precision, accuracy, linearity, sensitivity of this assay. The CV was less than 10%. We present the results of correlations with Aca (Dade Behring) and Cobas Mira (Roche). The reagent cartridge in the instrument and the calibration are stable during 28 days.

[Measurement of urinary free cotinine. Comparison with the level of expired air carbon monoxide]. / Dosage de la cotinine urinaire libre. Deuxième partie: comparaison avec le taux de monoxyde de carbone dans l'air expiré.

BACKGROUND AND AIM: Cotinine is a very reliable index for the estimation of active or passive smoking. Sampling from a single urine void is well accepted by smokers who are willing to stop. It is not possible to exclude modification of urine cotinine according to beverage intake. The aim of this study was to determine if urine cotinine concentration must necessarily be adjusted to creatinine or not, by making comparison with expired air carbon monoxide. MATERIAL AND METHODS: Carbon monoxide was measured in 53 smokers coming for the first time in a smoking cessation program. Urine cotinine was measured by HPLC-UV. The cut-off value for abstinence is 8ppm and 0.05 mg/L, repectively. Urine creatinine was determined using the Jaffe reaction. RESULTS: Mean CO level was 18.5 +/- 10.6 ppm and mean urine cotine was 1.45 +/- 0.86 mg/L. Eight smokers had CO 8 ppm. They should be considered as abstinent. However, only one of them had a cotinine under the detection limit. Urine creatinine varied in a large range (0.7 - 35 mmol/L). But, cotinine was only weakly correlated to creatinine (r = 0.279, p = 0.037). There was a highly significant correlation between cotinine and CO (0.649, p = 0.0001). The correlation of cotinine/creatinine versus CO was not significant (r = 0.249, p = 0.072). In order to take into account fluid intake, urine cotinine of each sample was adjusted as if creatinine was equal to the mean (8.3 mmol/L) of the group of subjects. The correlation observed with adjusted or non adjusted cotinine and CO (r = 0.640, p < 0.0001) was the same. CONCLUSION: Urine cotinine from a single void is an accurate index of tobacco smoking at the individual level. There is no need to adjust cotinine concentration, taking into account urine creatinine. Measurement of urine cotinine can be useful to manage smokers who deliberately wish to overcome tobacco dependence, offering the opportunity to provide an adequate level of nicotine substitutive therapy. It is also of peculiar importance to follow-up pregnant women and smokers for whom cessation is required after a clinical event. Finally, absence of cotinine in urine can be used to document abstinence from tobacco products.

[Urinary cotinine and nicotine metabolites measurement]. / Dosage urinaire de la cotinine et des métabolites de la nicotine.

UNLABELLED: According to the recent regulations (Circulaire DGS/DH du 3 avril 2000), tobacco dependence must be determined by the measurement of urine nicotine metabolites. Various assay methods are presently available. They were tested in order to evaluate their analytical performances and to determine how they can be used for the clinical management of smoking cessation. MATERIAL AND METHODS: Urine samples from a single void (n = 97) were obtained from active and abstinent smokers (with or without nicotine substitutive therapy). They were all analyzed by the various methods. Cotinine concentration was measured in six laboratories, using HPLC combined with UV detection according to a standardized procedure (Ann Biol Clin 2002 : 60 : 263-72). Immunoassay methods were also tested and the values obtained from urine samples were compared to urine cotinine measured by HPLC-UV. RESULTS: HPLC-UV: Urinary cotinine varied in a range from undetectable to 4 mg/L. An interlaboratory comparison was performed according to the Valtec procedure (calculation of equation of Deming, chart of differences). There was a good accordance between laboratories. Cotinine concentration was only slightly influenced by fluid intake, as shown by a poorly significant correlation between cotinine and creatinine (r = 0.23, p = 0.05). Homogeneous immunoassays: The two homogeneous immunoassays (Cotinine) from Thermo Electron and Cotinine Enzyme Immunoassay commercialized by Microgenics were highly correlated (r = 0.97). The correlation was not so strong with HPLC-UV (r = 0.86). Firstly, values were found higher with immunoassays because antibodies crossreact with 3-hydroxycotinine. Secondly, the ratio of immunoassays values to HPLC-UV values varied according to urine specimens. Finally, there was a highly significant correlation with urine creatinine (r = 0.40, p = 0.0001), thus indicating the influence of fluid intake. Heterogeneous immunoassay: The kit Metabolites of Nicotine commercialized by DPC France was tested on the analyzer Immulite, using a procedure specifically established for urine. Antibodies revealed a large spectrum of nicotine metabolites. Therefore, the values were much higher than those observed for the same urine samples with homogeneous immunoassays. CONCLUSION: HPLC-UV can be recommended for the measurement of urinary cotinine, as it was shown a good accordance between laboratories. The low detection limit is of interest for the diagnosis of Environmental Tobacco Smoking. Homogeneous immunoassays can be easily used for routine analysis as they can be performed directly on urine specimen. The results must be interpreted according to cut-off values specifically established according to homogeneous or heterogeneous immunoassays. Variability induced by fluid intake must be taken into account. The interest of the heterogeneous immunoassay needs to be confirmed for the diagnosis of Environmental Tobacco Smoking.

[Evaluation of Emit netilmicin and amikacin assays on Dimension RXL HM (Dade Behring) open channels]. / Adaptation des trousses Emit nétilmicine et amikacine sur canaux ouverts du Dimension RXL HM (Dade Behring).

The aim of this study was to evaluate and to validate an enzyme immunoassay in homogeneous phase for netilmicin and amikacin, adapted on the Dimension RXL HM (Dade Behring) machine. The results were compared with those obtained with automated polarization of fluorescence immunoassay using TDx FLx (Abbott). The protocol of the study and the analytical criteria were inspired by the protocol Valtec version 2002 recommended by the French Society of Clinical Biology (SFBC). The validation of this technique as adapted to the Dimension RXL HM has allowed its use for routine dosage adjustment of amikacin and netilmicin. The practicability is however the weak point of the adaptation of these techniques, even limiting as for their implementation.

[Biomarkers of tobacco smoke exposure]. / Les marqueurs spécifiques du tabagisme.

Tobacco smoking is a major risk factor for cancer, cardiovascular diseases and respiratory illnesses. Smoking is increasing among children and adolescents with subsequent consequences on the health. Furthermore, maternal tobacco smoking during pregnancy adversely affects prenatal growth. Nicotine, the most important tobacco alkaloid, is responsible for maintaining tobacco addiction. According to a recent Circulaire de la direction générale de la santé, nicotine dependence should be determined through questionnaires and quantitative estimate of nicotine metabolites. Nicotine blood level fluctuates and urinary nicotine excretion is of short duration. Nicotine is intensively metabolized in the liver and oxidized into cotinine. Urinary measurement of cotinine appears to be highly related with the degree of intoxication and to allow the differentiation between non exposed and exposed non-smokers. In order to check the present application of nicotine metabolites measurement, a survey was conducted in 340 smoking cessation units. Forty percent physicians (n = 137) answered the survey. For 17% of them, the quantification of nicotine metabolites is included in their daily practise and for 79%, guidelines about cotinine measurement should be given in France. Sixty-seven biologists answered the survey. Recommendations for immunoassay and HPLC determination of cotinine should be given as reported by 66 and 44% of them respectively. Indeed, urinary cotinine measurement with high performance liquid chromatography is highly sensitive and specific. However, immunoassays are more convenient. These two approaches are presently under investigation in order to provide guidelines for optimal use in various clinical situations. Traditional measures for nicotine dependence are the number of cigarettes smoked per day, nicotine intake expressed as mg per day, Fagerstr m questionnaire, expired air carbon monoxide, thiocyanates and cotinine levels in biological fluids. Urinary cotinine measurement is the most useful for the follow-up of smoking cessation including adjustment of nicotine replacement therapy, especially after a clinical event or for the follow-up of smoking pregnant women. It allows the detection of passive smoke exposure in children who are hospitalized for recurrent respiratory illnesses.

[Critical analysis of different methods used for toxicology screening in emergency laboratory]. / Analyse critique des différentes méthodes utilisées pour le dépistage toxicologique dans un laboratoire d'urgence.

Emergency analysis in toxicology is a difficult exercise. It involves in diagnosis, prognosis and the treatment of intoxication. Several methods exist in emergency screening. We have distinguished three large groups. Based on specificity: screening methods of medicament family (chemical methods and immunoassays) with benzodiazepines, tricyclic antidepressants, barbiturates and phenothiazines; complementary screening methods (thin layer chromatography and high pressure liquid chromatography) for a wider screening and finally quantitative methods (enzymatic, immunoassay, spectrometry and chromatography) specific to a molecule. The first group allows a rapid qualitative research according to medicament class but lacks specificity. The second group represented by the Remedi system, offers a larger screening of molecules but is more expensive and cannot detect classic molecules. The third group allows a precise dosage but is restricted to one molecule. We need one or the other of methods following clinical context and the type of molecule. In our laboratory, we have eliminated barbiturates and benzodiazepines research. We search only tricyclic antidepressants, salicylates and paracetamol. The Remedi system acts as a complement. It is essential to have a good knowledge of the limits and specificity of each method in order to allow the clinician to see the interpretation of the given result. The execution period and the quality of analytical result depend on dialogue between analyst and clinician before and after analysis.

[Value of the Remedi chromatography automate for the analytic diagnosis of drug poisoning]. / Intérêt de l'automate de chromatographie Remedi pour le diagnostic analytique des intoxications médicamenteuses.

The aim of this study was to evaluate the liquid chromatographic system Remedi (Biorad) in comparison with traditional immunological and colorimetric methods, for the diagnosis of acute drug overdose. 469 blood samples and 95 stomach cleaning liquid samples have been analysed during 1995. The usual toxicologic analysis was composed of the benzodiazepines, tricyclic antidepressants and barbiturates research. Ethanol, meprobamate and acetaminophen assays were performed only on physician's request. Only three pharmacological classes can be analysed both with immunological methods and Remedi: benzodiazepines, tricyclic antidepressants and barbiturates. Remedi has been found to be less sensitive than immunological method for benzodiazepines, it sometimes gave false negative results for barbiturates, but it was very efficient for antidepressants. Remedi often identified drugs other than the 3 previous classes: sedatives, antipsychotic, beta-blockers, antiarythmics. Furthermore these drugs are of clinical importance due to the fact that they are able to modify the symptomatology. In every case Remedi was able to give an estimation of the blood concentration of the toxic molecule matched. Remedi can not replace traditional methods but is a good complementary tool, available in emergency. This is particularly useful when clinical signs do not correspond to the toxics suspected by questioning the patient or relatives.

[Compared diagnostic performances of CKMB measurements by immuno-inhibition and three immunoenzyme methods for the early diagnosis of myocardial infarction]. / Performances diagnostiques comparées des mesures de la CKMB par immuno-inhibition et par trois méthodes immunoenzymologiques pour le diagnostic précoce de l'infarctus du myocarde.

In 98 patients consecutively admitted in a medical intensive care unit, an aliquot taken from the blood sample withdrawn for the cardiac enzyme admission request has been frozen. After thawing of these 98 aliquots total CK and the creatine kinase MB isoenzyme were measured on the same day. For this last determination, four methods were used and compared: an immunoinhibition method (Merck) and three immunoenzymatic assays (Abbott on IMX; Baxter on Stratus II; Hybritech on single use Icon cylinder). In 19 out of the 98 patients studied the diagnosis of myocardial infarction was made retrospectively by a cardiologist. This diagnosis was established according to the criteria defined by the WHO. The clinical performances (sensitivity, specificity, positive predictive value, negative predictive value) have been calculated for each test according to the following criteria: on the one hand, a cut-off of 8% (reference range of our laboratory) for the immunoinhibition technique; on the other hand, a cut-off defined by the manufacturer together with a cut-off obtained from the ROC curves for the three immunoenzymatic assays. Our results clearly demonstrate that the clinical performances of the three immunoenzymatic CKMB assays are very comparable and appear to be much better than the immunoinhibition method which should be abandoned.

Biochemical modifications in the blood and the heated fluids during intraperitoneal chemohyperthermia.

The biochemical changes in blood during intraperitoneal chemohyperthermia (IPCH) were examined by carrying out complete assessments before and after the operation. These assessments were made up of 23 parameters: Na, K, Cl, CO2, urea, creatinine, proteins, glucose, calcium, phosphates, magnesium, bilirubin, uric acid, lactic acid, CRP, ASAT, ALAT, CK, LDH, gamma-GT, ALP, lipase, and amylase. Only 5 of these parameters showed significant changes: proteins, urea, ALP, gamma-GT, lactic acid. The protein and urea levels decreased due to hemodilution induced by the perfusion of fluids. ALP and gamma-GT levels decreased, possibly due to localized inhibition of secretion. Lactic acid levels increased due to the movement of lactates from the heated fluid into the blood. The study of biochemical changes within the heated fluids was made using the following parameters: CA 125, CA 19-9, CEA, ASAT, ALAT, CK, LDH, gamma-GT, ALP, lipase, uric acid, phosphates, proteins, Na, K, Cl, urea, creatinine, and magnesium. Between the beginning and the end of IPCH, significant increases were found in the levels of CA 125 (+173%), proteins (+190%), ASAT (+130%), LDH (+103%), K+ (+232%), PO4 (+134%), and uric acid (+99%). These increases indicate the existence of a significant degree of cellular lysis.

[Evaluation of enzymuria as a tracer in nephrotoxicity: results of a multicenter study]. / Evaluation de l'enzymurie comme marqueur de néphrotoxicité: résultats d'une expérience multicentrique.

Urinary excretion of three enzymes of different subcellular location in kidney tissue, alanine aminopeptidase (AAP), gammaglutamyltransferase (GGT), N acetyl-beta-D glucosaminidase (NAG), was carried out in 79 healthy adults and 108 healthy children and in 69 adults with various therapies: antibiotics (32 cases), non steroidal anti-inflammatory drugs (NSAIDs) (22 cases), cisplatinum (12 cases) and cyclosporine (3 cases). A circadian rhythm has been shown in children. In patients treated with antibiotics, the importance and duration of the increased enzymes urinary excretion were variable but the excretion of AAP was always higher than that of GGT and NAG. Short term therapies by NSAIDs were without influence on enzymuria but long term therapies produced a moderate increase of NAG excretion. Enzymuria increased immediately after cisplatinum administration and decreased after each daily dose, except in patients with previously high creatininemia. Cyclosporine induced a slight increase in AAP and NAG excretion. Enzymuria, thus, increased early reflecting a toxic effect of the drug at the cellular level whereas creatininemia increase, marker of renal fonctionnal insufficiency, occurs only occasionally and lately.