Factors predicting the outcome of allergen-specific nasal provocation test in children with grass pollen allergic rhinitis.

Background: Nasal provocation testing (NPT) is a reference methodology to identify the culprit allergen in patients with allergic rhinitis. Selecting the right allergen for NPT is particularly difficult in poly-sensitized patients with seasonal allergic rhinitis (SAR). Predictors of NPT outcomes may facilitate the proper use of this test or even substitute it. Objective: To identify predictors of grass pollen NPT outcome from an array of clinical data, e-diary outcomes, and allergy test results in poly-sensitized pediatric patients with SAR. Methods: Poly-sensitized, SAR patients with grass pollen allergy, participating in the @IT.2020 pilot project in Rome and Pordenone (Italy), participated in a baseline (T0) visit with questionnaires, skin prick testing (SPT), and blood sampling to measure total (ImmunoCAP, TFS, Sweden) and specific IgE antibodies to grass pollen extracts and their major allergenic molecules (ESEP, Euroimmun Labordiagnostika, Germany). During the pollen season, patients filled the AllergyMonitor® e-diary app measuring their symptoms, medication intake, and allergy-related well-being via the Visual Analogue Scale (VAS). After the pollen season (T1), patients answered clinical questionnaires and underwent a nasal provocation test (NPT) with grass pollen extract. Results: We recruited 72 patients (age 14.3 ± 2.8 years, 46 males) sensitized to grass and/or other pollens, including olive (63; 87.5%) and pellitory (49; 68.1%). Patients positive to grass pollen NPT (61; 84.7%), compared to the negative ones, had worse VAS values in the e-diary, larger SPT wheal reactions, and higher IgE levels, as well as specific activity to timothy and Bermuda grass extracts, rPhl p 5 and nCyn d 1. A positive NPT to grass pollen was predicted by an index combining the specific activity of IgE towards Phl p 5 and Cyn d 1 (AUC: 0.82; p < 0.01; best cut-off ≥7.25%, sensitivity 70.5%, specificity: 90.9%). VAS results also predicted NPT positivity, although with less precision (AUC: 0.77, p < 0.01; best cut-off ≥7, sensitivity: 60.7%, specificity: 81.8%). Conclusions: An index combining the specific activity of IgE to rPhl p 5 and nCyn d 1 predicted with moderate sensitivity and high specificity the outcome of a grass pollen NPT in complex, poly-sensitized pediatric patients with seasonal allergic rhinitis. Further studies are needed to improve the index sensitivity and to assess its usefulness for NPT allergen selection or as an alternative to this demanding test procedure.

Surveillance of healthcare acquired infections by "alert microorganisms": preliminary results.

BACKGROUND: We evaluated the trend of four years (2015 - 2018) of "alert organisms" surveillance carried out at the 450 bed teaching hospital S. Andrea in Rome. METHODS: All patients with an "Alert organism" isolation were screened. In accordance with definitions used by the Centers for Disease Control patients with an "alert organism" isolation were evaluated for infection or colonization, by an infection control team (ICT). RESULTS: Between April 2015 and December 2018 a total 4,762 specimens with "Alert organism" isolation were screened and 1,601 patients were surveyed and included in the study. Overall 780 (48.8%) patients developed an healthcare acquired infection (HAI) at our institution, whereas 311 (19.4%) entered with a community acquired infection, 254 (15.8%) with an infection acquired in another healthcare setting and 256 (16.0%) resulted simply colonized. The 780 patients who developed an HAI at our institution presented 878 infectious episodes and the isolation of 931 microorganisms. C. difficile infections were the most common (27.2%), followed by 21.3% respiratory tract infections, 16.9% urinary tract infections, 15.5% surgical site infections, 12.5% bloodstream infections, 3.6% ulcers and 3.0% others. Among HAI group Gram negatives (54.1%) were more frequent than Gram positives (45.9%), whereas in patients entering in the hospital already with a community infection Gram positives overpassed Gram negatives (58.7% vs. 41.3%; p<0.001). Most common pathogens responsible for HAI were C. difficile (25.6%), Klebsiella spp. (25.5%), MRSA (19.6%) and Acinetobacter spp. (15.3%). Notably 30.0% HAI at other institutions were represented by C. difficile. Impressively, >40% of community acquired infections were related to MRSA. CONCLUSIONS: The present study provided some useful insight into the major multi-resistant pathogens epidemiology at our institution. The Authors succeeded in organizing a multidisciplinary ICT that created a partnership feeling with the hospital personnel.

Contact precaution procedures in healthcare facilities.

BACKGROUND: Multidrug resistance is an established and growing worldwide public health problem, since few therapeutic options remain available. MRSA is the leading Gram-positive organism which has spread both in the community and healthcare environment. Gram-negative bacteria, either fermenter (enterobacteriaceae) or nonfermenter, pose a major challenge to the healthcare providers because they can express a wide multidrug resistance. METHODS: Specific keywords combinations were analitically searched in PubMed and Scopus databases. Publications concerning contact precaution procedures were reviewed. RESULTS: The review on infection control and isolation precautions was carried out focusing on bundles that could help healthcare personnel to improve their action. CONCLUSIONS: This paper clearly refers to measures in order to control the spread of infectious disease. We provided some synthetic tables that could improve healthcare workers knowledge and help them to apply all fundamental concepts in infection control.

Excess length of hospital stay due to healthcare acquired infections: methodologies evaluation.

BACKGROUND: Healthcare acquired infections (HAI) cause an increase of burden and in particular excess length of hospital stay (LOS) accounts for approximately up to 90% of total costs. Therefore accurate estimation of extra hospital stay due to healthcare acquired infections is very important. METHODS: The authors carried out a review comparing the principal methods internationally used for estimating the excess LOS attributable to healthcare acquired infections. RESULTS: The methods described and analysed are: 1) Implicit physician assessment; 2) appropriateness evaluation protocol; 3) unmatched case-control; 4) matched case-control; 5) regression analysis; 6) multistate model. The various methodologies are described underlining advantages and limits which researchers need to know before starting any economic analysis. CONCLUSIONS: Overall, studies taking into account the time-dependent nature of HAI show to give more precise and reliable results.

Healthcare Associated Infections: educational intervention by "Adult Learning" in an Italian teaching hospital.

BACKGROUND: An educational intervention for HAI prevention based on a combination of training, motivation and subsequent application in the current clinical practice in an Italian teaching hospital. METHODS: In 2015-2016 a pilot mandatory training on HAI targeted to HCWs was organized in the 450 bed teaching hospital Sant'Andrea in Rome. By adopting the "Impact/control matrix" prioritization tool, the relative level of impact (risk in causing or favoring HAI) and control (possibility for HCWs to prevent HAI) attributed by the participants to the issues associated to HAI during their working groups was evaluated. RESULTS: Overall, 34 physicians, 43 nurses and 15 non clinical professionals participated actively in seven courses, identifying 58 different issues related to HAI, which were reported 128 times. Results showed frequently that, within the same type of issue, HCW referred various levels of impact (risk in causing or favoring HAI) and personal control (possibility for HCW to prevent HAI). Overall staff shortage was the most reported problem by HCW in our hospital. Also hand washing was regarded as a main problem, but HCW expressed the feeling that individuals could act more successfully on this issue (high or medium control). Results showed that staff frequently did not know how to handle correctly visitors, similarly many colleagues expressed some difficulty in communicating information to patients and relatives on HAI. Surprisingly, "antimicrobial therapy" and "excessive invasive procedures" were not particularly highlighted by the personnel. HCW expressed satisfaction for the course approac. CONCLUSIONS: The study showed an overall good level of knowledge regarding the importance and principles of infection control in our teaching hospital HCW. However personnel perceived a variability in the impact of many issues on HAI and even more on the personal possibility to control their effect. In order to improve HCW compliance with HAI prevention programs, the "Adult Learning" model seems to be very useful.

Point prevalence surveys on healthcare acquired infections in medical and surgical wards of a teaching hospital in Rome.

BACKGROUND: Healthcare acquired infections (HAI) are an important cause of morbidity and mortality in hospitals worldwide. Aim of the study was to analyze nine years surveillance activity, carried out by point prevalence surveys from 2007 to 2015, in a 450-bed teaching hospital in Rome. METHODS: Point prevalence surveys were carried out every year in the medical and surgical wards following the same methodology. In accordance with definitions used by the Centers for Disease Control, all infections occurred more than 48 hours after hospital admission were considered HAI, and included in the study. Baseline characteristics, clinical features, isolated pathogens (only for the period 2011-2015) and antimicrobial resistance were recorded. RESULTS: During the nine years point prevalence surveys a total 2,840 patients were enrolled. Overall 136 (4.79%) patients developed 180 (6.34%) HAI. The most frequent HAI were respiratory tract infections (RTI), which accounted for 35.0% of all HAI, followed by surgical site infections (SSI) 22.2%, urinary tract infections (UTI) 19.4%, bloodstream infections (BSI) 17.2%, and others 6.1%. HAI related to major invasive risk procedures were also evaluated. SSI/patients undergoing surgery 3.99%, UTI/ patients with urinary catheter 4.17% and BSI/patients with CVC 9.42%. Over one-half of all patients surveyed (1,532, 53.9%) were receiving antibiotics at the time of our study. Among them 892 (58.2%) for treatment, 641 (41.8%) for prophylaxis. In the latter group, 109 (17.0%) underwent extra-short term, 89 (13.9%) short term and 443 (69.1%) a long term prophylaxis. During the period 2011-2015 out of 110 HAI episodes 71 (64.5%) were confirmed microbiologically. In total 106 pathogens were isolates, Gram-negative bacteria (63.2%) were isolated more frequently than Gram-positive bacteria (28.3%). CONCLUSIONS: The overall HAI prevalence in our hospital was consistent with those reported in other studies in Italy. The study underlined the role of Gram-negative bacteria in HAI and the need for antimicrobial stewardship. It also provided useful baseline data for rational priorities in allocation of resources, for further infection control activities.

Distribution and determinants of urinary biomarkers of exposure to organophosphate insecticides in Puerto Rican pregnant women.

Globally, human exposures to organophosphate (OP) insecticides may pose a significant burden to the health of mothers and their developing fetuses. Unfortunately, relevant data is limited in certain areas of the world concerning sources of exposure to OP insecticides in pregnant populations. To begin to address this gap in information for Puerto Rico, we studied repeated measures of urinary concentrations of 10 OP insecticide metabolites among 54 pregnant women from the northern karst region of the island. We also collected demographic data and self-reported information on the consumption of fruits, vegetables, and legumes in the past 48 h before urine collection and home pest-related issues. We calculated the distributions of the urinary biomarkers and compared them to women of reproductive age from the general U.S. population. We also used statistical models accounting for correlated data to assess within-subject temporal variability of the urinary biomarkers and to identify predictors of exposure. We found that for all but two metabolites (para-nitrophenol [PNP], diethylthiophosphate [DETP]), 50th or 95th percentile urinary concentrations (the metric that was used for comparison was based on the biomarker's detection frequency) of the other eight metabolites (3,5,6-trichloro-2-pyridinol [TCPY], 2-isopropyl-4-methyl-6-hydroxy-pyrimidine, malathion dicarboxylic acid, diethylphosphate, diethyldithiophosphate, dimethylphosphate, dimethylthiophosphate [DMTP], dimethyldithiophosphate) were somewhat lower in our cohort compared with similarly aged women from the continental United States. TCPY, PNP, DETP, and DMTP, which were the only urinary metabolites detected in greater than 50% of the samples, had poor reproducibility (intraclass correlation coefficient range: 0.19-0.28) during pregnancy. Positive predictors of OP insecticide exposure included: age; marital or employment status; consumption of cherries, grape juice, peanuts, peanut butter, or raisins; and residential application of pesticides. Further research is needed to understand what aspects of the predictors identified influence OP insecticide exposure during pregnancy.

Impact of low-level gestational exposure to organophosphate pesticides on neurobehavior in early infancy: a prospective study.

BACKGROUND: National data suggest widespread gestational exposure to organophosphate pesticides (OPs) based on the detection of OP metabolites in the urine of pregnant women. Associations with early infant neurobehavior are largely understudied, with only two studies reporting abnormal reflexes in newborns in association with gestational exposure to OPs. Our objective was to utilize biological markers of OP metabolites in pregnant women and a comprehensive assessment of infant neurobehavior to determine the association of gestational exposure to OPs with neurobehavioral outcomes during early infancy. METHODS: Among a cohort of 350 mother/infant pairs, we measured six common dialkylphosphate metabolites of OP pesticides in maternal urine, at two times during pregnancy (16 w & 26 w gestation), then calculated aggregate concentrations of diethylphosphate, dimethylphosphate, and total dialkyphosphate metabolites. We measured infant neurobehavior at about five weeks of age using the NICU Network Neurobehavioral Scale (NNNS), a comprehensive assessment of neurobehavior in young infants. Analyses of associations between gestational exposure to OPs and neurobehavior at five weeks included multiple linear and logistic regression. RESULTS: After adjustment for covariates, higher creatinine-corrected urinary concentrations of diethylphosphate metabolites were associated with improved attention and reduced lethargy and hypotonia in young infants. Higher creatinine-corrected urinary concentrations of total dialkylphosphate metabolites were associated with fewer signs of autonomic stress. Women who were white, married, had advanced education, and reported more frequent consumption of fresh fruits and vegetables had higher concentrations of OP metabolites during pregnancy. CONCLUSIONS: In this sample of pregnant women whose urinary concentrations of dialkylphosphate metabolites are representative of national exposure levels, we found no detrimental effects of gestational exposure to OPs on neurobehavioral outcomes among young infants. These results are important as they suggest there may be minimal to no detectable adverse impact of low level prenatal OP exposure on the neurobehavior of young infants.

Validation of healthcare administrative data for the diagnosis of epilepsy.

BACKGROUND: Administrative databases have become an important tool to monitor diseases. Patients with epilepsy could be traced using disease-specific codes and prescriptions, but formal validation is required to obtain an accurate case definition. The aim of the study was to correlate administrative data on epilepsy with an independent source of patients with epilepsy in a district of Lombardy, Northern Italy, from 2000 to 2008. METHODS: Data of nearly 320 600 inhabitants in the district of Lecco collected from the Drug Administrative Database of the Lombardy Region were analysed. Among them were included patients who fulfilled the International Classification of Diseases 9 (ICD-9) codes and/or the disease-specific exemption code for epilepsy and those who had at least one EEG record and took antiepileptic drugs (AEDs) as monotherapy or in variable combinations. To ascertain epilepsy cases, 11 general practitioners (GPs) with 15 728 affiliates were contacted. Multiple versions of the diagnostic algorithm were developed using different logistic regression models and all combinations of the four independent variables. RESULTS: Among the GP affiliates, 71 (4.5/1000) had a gold standard diagnosis of epilepsy. The best and most conservative algorithm included EEG and selected treatment schedules and identified 61/71 patients with epilepsy (sensitivity 85.9%, CI 76.0% to 92.2%) and 15 623/15 657 patients without epilepsy (specificity 99.8%,CI 99.7% to 99.8%). The positive and negative predictive values were 64.2% and 99.9%. Sensitivity (86.7%) and the positive predictive value (68.4%) increased only slightly when patients with single seizures were included. CONCLUSIONS: A diagnostic algorithm including EEG and selected treatment schedules is only moderately sensitive for the detection of epilepsy and seizures. These findings apply only to the Northern Italian scenario.

FLOTAC can detect parasitic and pseudoparasitic elements in reptiles.

Reptiles have increased in popularity worldwide; snakes and lizards are frequently used as pets. As a consequence of their popularity, the interest of the scientific community in these animals has increased. In order to acquire epidemiological data on the parasitic infections affecting reptiles in Italy a survey was carried out in 125 snakes and 25 lizards bred in the Campania region of southern Italy. Individual fecal samples were collected and FLOTAC was used for copromicroscopic diagnosis. Eimeriidae, oxyurids, strongylids, other gastro-intestinal nematodes and pulmonary nematodes were the most representative parasites found. Eggs of pseudoparasites (mites, oxyurids and trichurids affecting rodents) were also found. The use of FLOTAC for diagnosis of parasitic infections in reptiles has demonstrated to be a rapid and sensitive test to improve diagnosis and acquire new information on the parasitological fauna of reptiles.

High-throughput sample preparation for the quantitation of acephate, methamidophos, omethoate, dimethoate, ethylenethiourea, and propylenethiourea in human urine using 96-well-plate automated extraction and high-performance liquid chromatography-tandem mass spectrometry.

Acephate, methamidophos, o-methoate, and dimethoate are organophosphorus pesticides, and ethylenethiouria and propylenethiourea are two metabolites from the bisdithiocarbamate fungicide family. They are some of the most widely used pesticides and fungicides in agriculture both domestically and abroad. The existing high-performance liquid chromatography (HPLC)-tandem mass spectrometry (MS/MS) method for the measurement of these compounds in human urine was improved by using a 96-well plate format sample preparation; the use of HPLC-MS/MS was comparable with a concentration range of 0.125 to 50 ng/ml. Deuterium-labeled acephate, ethylenethiouria, and methamidophos were used as internal standards. The sample preparation procedure, in the 96-well format with a 0.8-ml urine sample size, uses lyophilization of samples, followed by extraction with dichloromethane. The analytes were chromatographed on a Zorbax SB-C3 (4.6 × 150 mm, 5.0-µm) column with gradient elution by using 0.1% formic acid in aqueous solution (solvent A) and 0.1% formic acid in methanol (solvent B) mobile phase at a flow rate of 1 ml/min. Quantitative analysis was performed by atmospheric pressure chemical ionization source in positive ion mode using multiple-reaction monitoring of the precursor-to-product ion pairs for the analytes on a TSQ Quantum Ultra HPLC-MS/MS. Repeated analyses of urine samples spiked with high (15 ng/ml), medium (5 ng/ml), and low (1 ng/ml) concentrations of the analytes gave relative SDs of <13%. The limits of detection were in the range of 0.004-0.01 ng/ml. The method also has high accuracy, high precision, and excellent extraction recovery. Furthermore, the improved sample preparation method decreased the cost and labor required while effectively doubling the analytic throughput with minimal matrix effect.

Quantification of cyanuric acid residue in human urine using high performance liquid chromatography-tandem mass spectrometry.

Concern has increased about the resulting health effects of exposure to melamine and its metabolic contaminant, cyanuric acid, after infants in China were fed baby formula milk products contaminated with these compounds. We have developed a selective and sensitive analytical method to quantify the amount of cyanuric acid in human urine. The sample preparation involved extracting free-form cyanuric acid in human urine using anion exchange solid phase extraction. Cyanuric acid was separated from its urinary matrix components on the polymeric strong anion exchange analytical column; the analysis was performed by high performance liquid chromatography-tandem mass spectrometry using negative mode electrospray ionization interface. Quantification was performed using isotope dilution calibration covering the concentration range of 1.00-200ng/mL. The limit of detection was 0.60ng/mL and the relative standard deviations were 2.8-10.5% across the calibration range. The relative recovery of cyanuric acid was 100-104%. Our method is suitable to detect urinary concentrations of cyanuric acid caused by either environmental exposures or emerging poisoning events.

Urinary complications from breast cancer metastasis: case report and review of the literature.

Breast cancer is the most prevalent malignant disease among women, with the exception of non-melanoma skin cancers. Malignant breast tumours metastasise to lungs, bone, liver, lymph nodes and skin, but the literature also reports few cases of unusual metastases such as to the bladder. We present the case of a 57-year-old woman affected by lobular invasive breast cancer and complaining of high urinary frequency with nicturia. To date this is the seventh reported case of isolated metastatis of breast carcinoma to the bladder.

Quantification of dialkylphosphate metabolites of organophosphorus insecticides in human urine using 96-well plate sample preparation and high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry.

Organophosphorus (OP) pesticides kill by disrupting a targeted pest's brain and nervous systems. But if humans and other animals are sufficiently exposed, OP pesticides can have the same effect on them. We developed a fast and accurate high-performance liquid chromatography-tandem mass spectrometry method for the quantitative measurement of the following six common dialkylphosphate (DAP) metabolites of organophosphorus insecticides: dimethylphosphate (DMP), dimethylthiophosphate (DMTP), dimethyldithiophosphate (DMDTP), diethylphosphate, (DEP), diethylthiophosphate (DETP), and diethyldithiophosphate (DEDTP). The general sample preparation included 96-well plate solid phase extraction using weak anion exchange cartridges. The analytical separation was performed by high-performance liquid chromatography with a HILIC column. Detection involved a triple quadrupole mass spectrometer with an ESI probe in negative ion mode using multiple reaction monitoring. Repeated analyses of urine samples spiked at 150, 90 and 32 ng/mL with the analytes gave relative standard deviations of less than 22%. The extraction efficiency ranged from 40% to 98%. The limits of detection were in the range of 0.04-1.5 ng/mL. The throughput is 1152 samples per week, effectively quadrupling our previous throughput. The method is safe, quick, and sensitive enough to be used in environmental and emergency biological monitoring of occupational and nonoccupational exposure to organophosphates.

An improved high-performance liquid chromatography-tandem mass spectrometric method to measure atrazine and its metabolites in human urine.

We report an improved solid-phase extraction-high-performance liquid chromatography-tandem mass spectrometry method with isotope dilution quantification to measure seven atrazine metabolites in urine. The metabolites measured were hydroxyatrazine (HA), diaminochloroatrazine (DACT), desisopropylatrazine (DIA), desethylatrazine (DEA), desethylatrazine mercapturate (DEAM), atrazine mercapturate (ATZM), and atrazine (ATZ). Using offline mixed-mode reversed-phase/cation-exchange solid-phase extraction dramatically increased recovery and sensitivity by reducing the influence of matrix components during separation and analysis. DACT extraction recovery improved to greater than 80% while the other analytes had similar extraction efficiencies as previously observed. Limits of detection were lower than our previous method (0.05-0.19 ng/mL) with relative standard deviations less than 10%. The total runtime was shorter (18 min) than the previous on-line method, thus it is suitable for large-scale sample analyses. We increased the throughput of our method twofold by using the newer extraction technique.

Measurement of ethyl methanesulfonate in human plasma and breast milk samples using high-performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry.

Ethyl methanesulfonate (EMS) is a mesylate ester, which is known to be a potent mutagen, teratogen, and possibly carcinogen. Mesylate esters have been found in pharmaceuticals as contaminants formed during the manufacturing process and may potentially pose an exposure hazard to humans. We have developed and validated a method for detection of trace amounts (ng/ml levels) of EMS in human plasma and breast milk. The samples were extracted by matrix solid-phase dispersion with ethyl acetate using Hydromatrix and the ASE 200 Accelerated Solvent Extractor. The extracts were separated by high-performance liquid chromatography (HPLC) using a HILIC column. The detection was performed with a triple quadrupole mass spectrometer (TSQ Quantum Ultra, Thermo Electron Corporation) using atmospheric pressure chemical ionization in negative-ion mode and multiple reaction monitoring. The use of a surrogate internal standard in combination with HPLC-MS/MS provided a high degree of accuracy and precision. The extraction efficiency was greater than 70%. Repeated analyses of plasma and breast milk samples spiked with high (100 ng/ml), medium (50 ng/ml) and low (5 ng/ml) concentrations of the analytes gave relative standard deviations of less than 12%. The limits of detection were in the range of 0.5-0.9 ng/ml for both matrices.

Method for measurement of the quaternary amine compounds paraquat and diquat in human urine using high-performance liquid chromatography-tandem mass spectrometry.

We have developed a highly selective and sensitive analytical method to quantify paraquat and diquat by use of high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The sample preparation includes solid phase extraction that uses weak cation exchange cartridges. These highly charged dual quaternary amines were not retained by standard reversed phase columns, but they could be adequately separated through HPLC with a HILIC column. The detection was carried out with a triple quadrupole mass spectrometer with an electrospray ionization probe in positive ion mode in multiple reaction monitoring. Repeated analysis in human urine samples spiked with low (5 ng/ml), medium (15 ng/ml), and high (30 ng/ml) concentrations of the analytes yielded relative standard deviations of less than 9%. The extraction efficiencies ranged from 77.7% to 94.2%. The limits of detection were in the range of 1 ng/ml.

Quantification of Paraquat, MPTP, and MPP+ in brain tissue using microwave-assisted solvent extraction (MASE) and high-performance liquid chromatography-mass spectrometry.

Animal models, consistent with the hypothesis of direct interaction of paraquat (PQ) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) with specific areas of the central nervous system have been developed to study Parkinson's disease (PD) in mice. These models have necessitated the creation of an analytical method for unambiguous identification and quantitation of PQ and structurally similar MPTP and 1-methyl-4-phenylpyridinium ion (MPP+) in brain tissue. A method for determination of these compounds was developed using microwave-assisted solvent extraction (MASE) and liquid chromatography-mass spectrometry. Extraction solvent and microwave conditions such as power and time were optimized to produce recoveries of 90% for PQ 78% for MPTP and 97% for its metabolite MPP+. The chromatographic separation was performed on a C8, column and detection was carried out using an ion trap as an analyzer with electrospray ionization. Mass spectrometer parameters such as heated capillary temperature, spray voltage, capillary voltage and others were also optimized for each analyte. Analysis was done in selective ion-monitoring (SIM) mode using m/z 186 for PQ, m/z 174 for MPTP, and m/z 170 for MPP+. The method detection limit for paraquat in matrix was 100 pg, 40 pg for MPTP, and 20 pg MPP+.

Urinary elimination kinetics of acephate and its metabolite, methamidophos, in urine after acute ingestion.

INTRODUCTION: Acephate (AP) is a widely available organophosphorus (OP) insecticide considered to have low mammalian toxicity. In plants and insects, AP is metabolized extensively to methamidophos (MP), a more potent OP insecticide. The limited mammalian metabolism of AP to MP has been studied in laboratory rat models and suggests that initial formation of MP from AP may inhibit further formation. No case reports of human ingestion with urine AP and MP levels have been previously published. CASE REPORT: A 4-year-old male being evaluated for altered mental status and head trauma was noted to have muscarinic and nicotinic cholinergic signs. Further history suggested possible ingestion of a commercial AP product at an unknown time. Ingestion of AP was confirmed by the presence of urinary AP and MP and severely depressed red blood cell (RBC) cholinesterase and pseudocholinesterase activity levels. The patient initially received atropine in two 0.02 mg/kg IV boluses, then was started on 0.05 mg/kg IV per hour and titrated accordingly to clinical signs of cholinergic toxicity. Pralidoxime was also given at 20 mg/kg IV bolus, followed by an infusion of 10 mg/kg per hour. The patient required mechanical ventilation for 18 days and atropine infusion for 20 days. After a complicated intensive care unit course, he recovered and was discharged after a total of 32 days of hospitalization. METHODS: Four urine samples collected at different times were analyzed for AP and MP by using high-performance liquid chromatography-atmospheric pressure chemical ionization tandem mass spectrometry. Kinetic calculations were performed by using standard equations. RESULTS: Suspected ingestion was confirmed by the presence of AP and MP in urine. The amount of MP found in urine suggests some limited human metabolism to this more toxic compound. CONCLUSIONS: Urinary elimination kinetics of AP demonstrates low metabolic conversion of AP to MP in humans.