Simple high-throughput analytical method using ultra-performance liquid chromatography coupled with tandem mass spectrometry to quantify total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol in urine.

BACKGROUND: Since the urinary concentration of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is a reliable biomarker of exposure to tobacco smoke, we developed a relatively simple high-throughput chromatographic method to quantify total urinary NNAL concentrations in the general population. METHODS: The high-throughput analytical method was developed using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) to identify and quantify total urinary NNAL concentrations in 10 non-smokers and 15 otherwise healthy smokers. RESULTS: Loss of nitric oxide at m/z 30 was found to be the predominant mass transitioned, and therefore was used as the SIM transition to quantify both NNAL and NNAL-methyl-d3 in urine. The analytical method did not require sample derivatization. Standard curves for total NNAL concentrations were linear between 20 and 1500 pg/mL, with coefficients of determination >0.95. Precision and accuracy ranged from 2.2% to 8.6% (CV) and from -5.6% to 10.9% (percent error), respectively. The lowest limit of quantification was 6.7 pg/mL, and 2.0 pg/mL the lowest limit of detection (LLOD). Total urinary NNAL concentrations in non-smoker subjects were

Dose-response and time-response analysis of total fatty acid ethyl esters in meconium as a biomarker of prenatal alcohol exposure.

OBJECTIVES: Little is known on how the dose and timing of exposure co-influence the cumulative concentration of fatty acid ethyl esters (FAEEs) in meconium. The objective of the study was to assess the cumulative concentration of FAEEs in meconium as a biomarker of light, moderate, or heavy prenatal alcohol exposure occurring at either first, second, or third trimesters of pregnancy. METHODS: History of prenatal alcohol exposure was obtained in the 34th week of gestation from 294 pregnant women. Meconium was collected from their babies within the first 6 to 12 h after birth and examined for the presence of nine FAEEs. RESULTS: No significant differences were identified between the cumulative levels of FAEEs in the meconium from the babies born to abstainers and those born to mothers with history of light-to-moderate prenatal alcohol exposure during their pregnancy. CONCLUSIONS: Light-to-moderate prenatal alcohol exposure cannot be reliably predicted by the cumulative FAEE concentrations in meconium of exposed babies. A cumulative FAEE level of >10 nmol/g would be required to consider that prenatal alcohol exposure during the second to third trimesters occurred at risky levels in the absence of reliable maternal history of ethanol exposure.

Obstetric and fetal outcomes in dystocic and eutocic sows to an injection of exogenous oxytocin during farrowing.

Sixty hybrid Yorkshire-Landrace penned sows, 30 with eutocic farrowing and 30 experiencing a dystocic parturition, were studied to evaluate the obstetric and neonatal outcomes to low doses of oxytocin administered at advanced stages of parturition. Animals in each group were randomly subdivided into 2 subgroups: 15 eutocic and 15 dystocic sows received oxytocin 0.083 IU/kg (equivalent to 1 IU/12 kg body weight), administered intramuscularly after the delivery of the 5th piglet; the other 15 eutocic and 15 dystocic sows received saline solution intramuscularly at the same time. Oxytocin decreased the number of intrapartum deaths by approximately 50% (P = 0.002). No piglet was born dead from the saline- and oxytocin-treated eutocic sows. The highest viability score was observed among piglets born to eutocic sows treated with oxytocin. In summary, this dose schedule would help to decrease the number of stillbirths in both eutocic and dystocic farrowing sows.

Could a first-trimester blood phosphatidylethanol concentration ⩾4 nM be useful to identify women with moderate-to-heavy prenatal alcohol exposure who are at high risk of adverse pregnancy outcomes?

It is accepted that blood phosphatidylethanol (PEth) concentrations are reliable biomarkers of ethanol (alcohol) exposure. We therefore conducted a preliminary study to test the hypothesis that elevated blood PEth concentrations can help to identifying women with prenatal alcohol exposure who are at higher risk of adverse pregnancy outcomes. The study included 35 first-trimester pregnant women who self-reported alcohol ingestion and had PEth blood concentration ⩾4 nM at recruitment. As a control group, 233 first-trimester pregnant women who self-reported as being either abstainers or light alcohol drinkers and had blood PEth concentrations <4 nM, were also included. All participants were followed up until completion of their pregnancies. Women with prenatal alcohol exposure and PEth concentrations ⩾4 nM had a risk ratio of spontaneous abortions of 3.21 (95%CI 0.93-11.06; P=0.074). Because of the potential implications in the prenatal care of women reporting risky alcohol exposure, the preliminary results from the present study indicate the need for testing the hypothesis in a more definitive approach.

Characterization of phosphatidylethanol blood concentrations for screening alcohol consumption in early pregnancy.

OBJECTIVE: Phosphatidylethanol (PEth) is formed endogenously by the direct action of ethanol, and has a half-life long enough to make it a reliable biomarker of alcohol exposure in early pregnancy. In this study, we aimed to characterize PEth blood concentrations to differentiate different levels of alcohol exposure in pregnant women. METHODS: The study consisted of 305 consecutive pregnant women who had been referred to our hospital for antenatal care. Of them, 117 self-reported alcohol ingestion in the first trimester of pregnancy and 188 were abstainers. Total PEth concentration in whole blood was quantified by liquid chromatography-mass spectrometry (LC-MS/MS). Alcohol ingestion was classified according to the United States National Institute on Alcohol Abuse and Alcoholism into light drinkers: ≤ 3 drinks/week, moderate drinkers: 3-7 drinks/week, and heavier drinkers: > 7 drinks/week (a standard drink = 14 g of ethanol). RESULTS: Participants had quantifiable PEth blood levels 3-4 weeks after the last drink. There were 4.8% abstainers who had positive PEth concentrations; all of them reported a positive history of alcohol consumption before conception. PEth blood concentrations were significantly correlated to drinks per occasion (r = 0.44; P < 0.001) and days drinking per week (r = 0.34; P < 0.001). However, almost 74% of participants with ≤ 3 drinks/week of alcohol, and 46% with 3-7 drinks/week, had PEth blood concentrations below the lower limit of quantification (LLOQ). The area under the curve (AUC) generated by a receiver operation characteristic curve (ROC) analysis increased as the cutoff value of PEth blood concentration increased. However, the cutoff values were below or close to the LLOQ. CONCLUSIONS: Our study presents a formal characterization of PEth blood concentrations for screening alcohol ingestion in first-trimester pregnant women. However, caution is recommended for overrepresenting either negative or positive results.

Quantitation of fatty acid ethyl esters in human meconium by an improved liquid chromatography/tandem mass spectrometry.

This paper reports the development and validation of an improved assay for quantitation of fatty acid ethyl esters (FAEEs) in human meconium using liquid chromatography/tandem mass spectrometry (LC-MS/MS). FAAEs (ethyl laurate, ethyl myristate, ethyl palmitate, ethyl palmitoleate, ethyl stearate, ethyl oleate, ethyl linoleate, ethyl linolenate, and ethyl arachidonate) and the internal standard (I.S.), ethyl heptadecanoate, were separated by reverse phase HPLC and quantified by MS/MS using electrospray ionization (ESI) and multiple reaction monitoring (MRM) in the positive ionization mode. The absolute recovery of FAEEs varied from 55+/-10% for 0.33 nmol/g (100 ng/g) of ethyl linoleate up to 86+/-8% for 1.55 nmol/g (500 ng/g) of ethyl miristate. The LODs and LOQs varied from 0.01 to 0.08 nmol/g and from 0.02 to 0.27 nmol/g, respectively. The assay has been successfully applied to examine the FAEE levels in 81 meconium samples from babies born to mothers reporting alcohol consumption, to varying degrees, during pregnancy.

Sexually transmitted infections associated with vulvovaginal symptoms in adolescents denying sexual activity.

OBJECTIVE: To identify clinical, laboratory and ultrasonographic evidence of a probable sexually transmitted infection associated with vulvovaginal symptoms in adolescents denying sexual activity. MATERIAL AND METHODS: The medical records of female adolescents, aged 10-18 years were reviewed. These women received first-time medical care for vulvovaginitis, between 1995 and 1999 at Hospital Infantil de México Federico Gómez, (Children's Hospital). Comparisons between groups were performed, as appropriate, by the unpaired Student's t-test, the Z test or the chi-square test; statistically significant differences were set at a two-tailed p < 0.05. Odds ratios with 95% confidence intervals were calculated. RESULTS: Of 258 adolescents with vulvovaginitis, 53 (20.5%) had a sexually transmitted microorganism and 52 of them denied ever having sexual activity. Age, education and socioeconomic level, development of sexual characters, and presence of menstruation did not differ between patients with and without sexually transmitted infections. The presence of sexually transmitted infections was associated with lower abdominal pain, abnormally colored vaginal discharge, a positive urine culture, and an abdominal ultrasonographic evidence, compatible with pelvic inflammatory disease (ultrasonographic odds ratio 144.8; 95% CI 51.0 to 411.3). CONCLUSIONS: There is an association between sexually transmitted infections in young women with vulvovaginitis and lower abdominal pain, abnormally colored vaginal discharge, a positive urine culture, and an abdominal ultrasonographic evidence compatible with pelvic inflammatory disease. The English version of this paper is available too at:http://www.insp.mx/salud/index.html.

Sexually transmitted infections associated with vulvovaginal symptoms in adolescents denying sexual activity

OBJETIVO: Identificar datos clínicos, de laboratorio y ultrasonográficos que permitan el diagnóstico de una infección de transmisión sexual asociada a síntomas vulvovaginales en las pacientes adolescentes que niegan vida sexual activa. MATERIAL Y MÉTODOS: Se revisaron los expedientes de las adolescentes de 10 a 18 años de edad que requirieron atención médica de primera vez por vulvovaginitis entre 1995 y 1999 en el Hospital Infantil de México Federico Gómez. Las comparaciones entre grupos se llevaron a cabo con la prueba t de Student, la prueba de Z, o la de ji-cuadrada. Se utilizó un valor de p<0.05 para establecer diferencias estadísticamente significativas. Se calcularon razones de momios con intervalos de confianza de 95%. RESULTADOS: De 258 adolescentes, en 53 (20.5%) se identificó un microrganismo de transmisión sexual y 52 de ellas negaron tener vida sexual activa. No hubo diferencias estadísticas entre los dos grupos de adolescentes en cuanto a la edad, los años de estudio, el nivel socioeconómico, la maduración sexual y la presencia de menarquia. El dolor abdominal en los cuadrantes inferiores, la coloración anormal de la secreción vaginal, un cultivo urinario positivo y un estudio ultrasonográfico abdominal compatible con enfermedad pélvica inflamatoria estuvieron asociados con infección de transmisión sexual. Con el estudio ultrasonográfico se obtuvo una razón de momios de 144.8 (intervalo de confianza 95% 51.0 a 411.3). CONCLUSIONES: Se demostró una asociación entre infección de transmisión sexual en adolescentes con vulvovaginitis y dolor abdominal bajo, secreción vaginal anormal, urocultivo positivo y un estudio ultrasonográfico compatible con enfermedad pélvica inflamatoria.