Una presentación no tan atípica: autismo en mujeres / Not an Atypical Presentation: Autism in Women

A pesar del conocimiento que tenemos en la actualidad de la amplia variedad de sintomatología y fenotipos de pacientes que engloban los Trastornos del Espectro Autista, algunos de estos fenotipos siguen sin estar claramente descritos en las clasificaciones psicopatológicas. Se propone un caso clínico de una paciente adolescente que consulta por sintomatología depresiva, descubriéndose tras la evaluación y durante la evolución un Trastorno del Espectro Autista subyacente que había pasado desapercibido

Despite current knowledge about the wide variety of symptoms and phenotypes of patients that meet criteria for Autism Spectrum Disorder, some of these phenotypes are still not clearly described in psychopathological classifications. A clinical case of a teenage patient who consults for depressive symptoms is proposed. After the evaluation, an underlying Autism Spectrum Disorder that had gone unnoticed was discovered

Stories of change: the text analysis of handovers in an Italian psychiatric residential care home.

WHAT IS KNOWN ON THE SUBJECT?: There is a growing emphasis on communication as a result of the move towards the more inclusive approach associated with the community-based rehabilitation model. Therefore, more importance is attached to handovers. Besides ensuring transfer of information, handovers enhance group cohesion, socialize staff members to the practices of the service and capture its organizational culture. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: While handovers are mainly used for information transfer and to manage the services' daily routine, this paper offers an insight on how handovers can be conceived as valuable instruments to document cultural and organizational change. Only a limited amount of studies has focused on handovers in mental healthcare settings, and most of them only consider the perspectives of psychiatric nurses, while embracing a broader perspective, this paper provides valuable insights into the perspectives of various service providers. The overcoming of the dichotomy deficit-based vs. recovery-oriented model is possible if professionals use handovers to reflect upon their practice and the ways in which their cultural models are affected by the environmental context. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Handovers are valuable instruments to document organizational change. It would be important for psychiatric and rehabilitation facilities to keep track of the handover records over time as they may provide insightful information about cultural change and the transformations in the core values and beliefs held by professionals. ABSTRACT: Handovers assure a timely and correct information transfer while socializing workers to the service's culture; however, no study describes them as instruments to document organizational change and only a few have focused on psychiatric settings. Aim To investigate the change in the culture of an Italian psychiatric residential care home as perceived by its mental health workers (MHWs) over the course of two decades. Method Emotional text analysis (ETA) was used to analyse the MHWs' handovers completed from 1990 to 2011. Results The analysis generated four clusters and three main factors illustrating the change in the MHWs' representations of the residential care home and its occupants. The factors showed: (1) the shift from an individualistic, problem-focused view to an inclusive, community-based approach; (2) the presence of a descriptive as well as a specialized language; and (3) the presence of a double focus: on patients and professionals. Conclusions Handovers transcripts document the following changes: (1) a shift from a symptom-based to a recovery-oriented approach; (2) a modification of the MHWs values towards an holistic view of the patient; (3) a growing importance assigned to accountability, services integration and teamwork. The paper shows that handovers can be used diachronically to document organizational change.

Psychological treatments for depression in pre-adolescent children (12 years and younger): systematic review and meta-analysis of randomised controlled trials.

The objective of this study was to evaluate the efficacy of psychological treatments for depression in pre-adolescent children, a disorder affecting 1-2 % of children in this age range. A systematic review of studies of psychological interventions to treat depressive disorder in pre-adolescent children (aged up to 12-years-old) was carried out. The primary outcome was level of depressive symptoms. Studies were found using Medline, PsycINFO, EMBASE and Web of Knowledge databases and selected on several criteria. Only randomised controlled trials were included. Where individual studies covered a broader age range (usually including adolescents up to age 18 years), authors of those studies were contacted and requested to provide individual patient level data for those aged 12 years and younger. 2822 abstracts were reviewed, and from these 124 full text articles were reviewed, yielding 7 studies for which we were able to access appropriate data for this review. 5 of these studies evaluated cognitive behaviour therapy (CBT). Combined results from these studies suggest that there is a lack of evidence that CBT is better than no treatment [standard mean difference -0.342 (95 % confidence interval -0.961, 0.278)], although the number of participants included in the trials was relatively small. The evidence for efficacy of family therapy and psychodynamic therapy is even more limited. The very limited number of participants in randomised controlled trials means that there is inconclusive evidence for the psychological treatment of depression in children aged 12 years and below. Given the prevalence and significant impact of this disorder, there is an urgent need to establish the effectiveness or otherwise of psychological intervention.

Trastornos psiquiátricos en los casos de suicidio consumado en un área hospitalaria entre 2007-2010 / Psychiatric disorders in cases of completed suicide in a hospital area in Spain between 2007 and 2010

Introducción: El suicidio es un importante problema de salud pública. Uno de los principales factores de riesgo conocidos para el suicidio es el padecimiento de patología psiquiátrica que se identifica en un 90-95% de suicidios consumados, incrementándose el riesgo si existe comorbilidad. Los resultados internacionales sobre la patología psiquiátrica más frecuente son dicotómicos, divididos entre los trastornos del humor y los trastornos psicóticos, si bien los datos en nuestro entorno sobre casos de suicidio consumado son muy escasos. Metodología: El presente estudio describe las características psiquiátricas y forenses de los casos de suicidio consumado (n=79) acontecidos en la región asistencial de un hospital psiquiátrico entre 2007 y 2010. Los datos forenses fueron obtenidos en el Instituto de Medicina Legal de Catalunya y los datos clínicos a partir de la revisión de las historias clínicas. Resultados: La mayoría de los sujetos fallecidos por suicidio consumado en la muestra de referencia fueron varones (78,5%) (IC 68,4%-87,3%). El 45,5% (IC 33,8%-57,1%) (35 de 77) de los fallecidos disponía de historia en el circuito de salud mental y/o toxicomanías de la zona, desconociéndose los antecedentes de dos de los fallecidos por tratarse de menores de edad. De los 35 individuos con historia en el circuito de salud mental, el 54,3% (IC 37,1%-71,4%) presentaba un trastorno afectivo; (37,1%, IC 22,9%-51,4%) trastorno depresivo; 14,3% (IC 2,9%-25,7%) trastorno bipolar y el 17,1% (IC 5,7%-31,4%) un trastorno del espectro psicótico. Además, el 48,6% presentaba comorbilidad psiquiátrica no relacionada con tóxicos y el 42,9% (IC 25,7%-60,0%) comorbilidad con trastornos relacionados con sustancias. Conclusiones: Las características psiquiátricas y forenses del fenómeno del suicidio consumado en nuestro entorno confirman los datos internacionales sobre una tasa elevada de patología psiquiátrica y un patrón característico en cuanto a metodología suicida (AU)

Introduction: Suicide is an important Public Health problem. One of the most relevant known risk factors for suicide is suffering from a mental health disorder, identified in up to 90-95% of completed suicides, with this risk being increased if comorbidity is present. Findings from international research on the most common psychiatric disorders are dichotomous, divided into mood disorders and psychotic disorders. In Spain, data of this kind are scarce. Methods: This study describes the psychiatric and forensic characteristics of completed suicide cases (n=79) ocurred in a psychiatric hospital healthcare area (in Spain), between 2007 and 2010. The forensic data were obtained from the Institute of Legal Medicine of Catalonia and the clinical data by reviewing the clinical records. Results: Most of the subjects in this sample were males (78.5%, 95% CI; 68.4%-87.3%). Almost half of the sample (45.4%, 95% CI; 33.8%-57.1%, 35/77) had records in the Mental Health Services Network (including substance misuse services). Two of the 79 were under 18, so we were not able to access the records. More than half (54.3%, 95% CI; 37.1%-71.4%) of those with psychiatric history suffered from a mood disorder; 37.1% (95% CI; 22.9%-51.4% from a depressive disorder; 14.3% (95% CI; 2.9%-25.7%) from a bipolar disorder, and 17.1% (95% CI; 5.7%-31.4%) suffered from a psychotic disorder. With regard to substance misuse, 42.9% (95% CI; 25.7%-60.0%) presented substance misuse, and 48.6% did not. Conclusions: Psychiatric and forensic characteristics of completed suicide in this Spanish sample confirm previous findings from international studies: there is a high rate of psychiatric disorders in those who complete suicide, and there is a specific pattern as regards the method used to complete it (AU)

Psychiatric disorders in cases of completed suicide in a hospital area in Spain between 2007 and 2010.

INTRODUCTION: Suicide is an important Public Health problem. One of the most relevant known risk factors for suicide is suffering from a mental health disorder, identified in up to 90-95% of completed suicides, with this risk being increased if comorbidity is present. Findings from international research on the most common psychiatric disorders are dichotomous, divided into mood disorders and psychotic disorders. In Spain, data of this kind are scarce. METHODS: This study describes the psychiatric and forensic characteristics of completed suicide cases (n=79) ocurred in a psychiatric hospital healthcare area (in Spain), between 2007 and 2010. The forensic data were obtained from the Institute of Legal Medicine of Catalonia and the clinical data by reviewing the clinical records. RESULTS: Most of the subjects in this sample were males (78.5%, 95% CI; 68.4%-87.3%). Almost half of the sample (45.4%, 95% CI; 33.8%-57.1%, 35/77) had records in the Mental Health Services Network (including substance misuse services). Two of the 79 were under 18, so we were not able to access the records. More than half (54.3%, 95% CI; 37.1%-71.4%) of those with psychiatric history suffered from a mood disorder; 37.1% (95% CI; 22.9%-51.4% from a depressive disorder; 14.3% (95% CI; 2.9%-25.7%) from a bipolar disorder, and 17.1% (95% CI; 5.7%-31.4%) suffered from a psychotic disorder. With regard to substance misuse, 42.9% (95% CI; 25.7%-60.0%) presented substance misuse, and 48.6% did not. CONCLUSIONS: Psychiatric and forensic characteristics of completed suicide in this Spanish sample confirm previous findings from international studies: there is a high rate of psychiatric disorders in those who complete suicide, and there is a specific pattern as regards the method used to complete it.

A new composite model including metabolic syndrome, alanine aminotransferase and cytokeratin-18 for the diagnosis of non-alcoholic steatohepatitis in morbidly obese patients.

BACKGROUND: Non-invasive approaches are useful to differentiate simple steatosis from non-alcoholic steatohepatitis (NASH) in obese and morbidly obese patients. AIM: To develop a new scoring system to diagnose definitive NASH. METHODS: Preoperative clinical and biological data including serum caspase 3-generated cytokeratin-18 fragments (CK18) and surgical liver biopsies were obtained from 464 morbidly obese patients who had undergone bariatric surgery. The cohort was divided into two groups: training group (n = 310) and validation group (n = 154). Definitive NASH was defined according to Kleiner's classification with a Non-alcoholic fatty liver disease Activity Score (NAS) ≥5. RESULTS: Alanine aminotransferase (ALT), CK18 fragments and the presence of metabolic syndrome were independent predictors for discriminating patients with NAS ≥5 in the training group. These three parameters were used to carry out a scoring system for the prediction of NAS ≥5. Whereas serum CK18 fragment alone had an area under the receiver operating characteristic (AUROC) curve = 0.74, AUROC curves of the scoring system were 0.88 and 0.83 in the training group and the validation group, respectively. CONCLUSION: A simple and non-invasive composite model (the Nice Model) including metabolic syndrome, ALT and CK18 fragments is able to predict accurately a non-alcoholic fatty liver disease activity score ≥5 in morbidly obese subjects.

An integrated approach to biomonitoring exposure to styrene and styrene-(7,8)-oxide using a repeated measurements sampling design.

The aim of this work was to investigate urinary analytes and haemoglobin and albumin adducts as biomarkers of exposure to airborne styrene (Sty) and styrene-(7,8)-oxide (StyOX) and to evaluate the influence of smoking habit and genetic polymorphism of metabolic enzymes GSTM1 and GSTT1 on these biomarkers. We obtained three or four air and urine samples from each exposed worker (eight reinforced plastics workers and 13 varnish workers), one air and urine samples from 22 control workers (automobile mechanics) and one blood sample from all subjects. Median levels of exposure to Sty and StyOX, respectively, were 18.2 mg m(-3) and 133 microg m(-3) for reinforced plastics workers, 3.4 mg m(-3) and 12 microg m(-3) for varnish workers, and <0.3 mg m(-3) and <5 microg m(-3) for controls. Urinary levels of styrene, mandelic acid, phenylglyoxylic acid, phenylglycine (PHG), 4-vinylphenol (VP) and mercapturic acids (M1+M2), as well as cysteinyl adducts of serum albumin (but not those of haemoglobin) were significantly associated with exposure status (controls

Urinary hydroxylated metabolites of polycyclic aromatic hydrocarbons as biomarkers of exposure in asphalt workers.

BACKGROUND: Fumes and vapours released during laying of hot asphalt mix have been recognised as a major source of exposure for asphalt workers. OBJECTIVES: We investigated the relationships between inhalation exposure to asphalt emissions and urinary biomarkers of polycyclic aromatic hydrocarbons (PAHs) in asphalt workers (AW, n=75) and in ground construction workers (CW, n=37). METHODS: Total polyaromatic compounds (PAC) and 15 priority PAHs in inhaled air were measured by personal sampling. Hydroxylated PAH metabolites (OH-PAHs) (2-naphthol, 2-hydroxyfluorene, 3-hydroxyphenanthrene, 1-hydroxypyrene, 6-hydroxychrysene and 3-hydroxybenzo[a]pyrene) were determined in urine spot samples collected in three different times during the work week. RESULTS: Median vapour-phase PAC (5.5 microg m(-3)), PAHs (

Aluminum determination in biological fluids and dialysis concentrates via chelation with 8-hydroxyquinoline and solvent extraction/fluorimetry.

We describe a simple, rapid, and sensitive fluorescence method for measurement of aluminum (Al) in human biological fluids, in dialysis solutions, and in tap water, which uses 8-hydroxyquinoline for ion chelation. The fluorescence intensity of the toluene-extracted metal chelate (excitation wavelength, 380 nm; emission wavelength, 504 nm) remains unchanged for over 48 h at room temperature. Fluorescence intensity is a linear function of the concentration of Al in the 2-1000 microg/L range with detection limits of 0.7-2 microg/L. A large excess of other ions normally found in biological fluids does not interfere in Al determination. The method developed was successfully used in assaying Al in serum and urine of reference subjects, in serum samples from patients undergoing long-term dialysis, and in dialysis solutions. Al concentrations, measured by this fluorimetric procedure, were compared with those obtained by Zeeman graphite-furnace atomic absorption spectrometry. A correlation coefficient of 0.98 was obtained. The proposed method could be used for routine analysis in clinical laboratories for accurate determination of aluminum in aqueous or biological fluids.

[Assessment of exposure to organic aromatic compounds and PAH in asphalt industry: the PPTP-POPA Study results]. / Valutazione dell'esposizione a composti organici aromatici e IPA nelle opere di asfaltatura: i risultati dello Studio PPTP-POPA.

Asphalt is a mixture of mineral matter and bitumen, its fumes contain about 1% of Polycyclic Aromatic Hydrocarbons (PAH), some of which are carcinogens. In the PPTP-POPA Study of Lombardy Region, a group of 100 asphalt workers (exposed to bitumen fumes and diesel exhausts) and a group of 47 ground construction operators (exposed only to diesel exhausts) were investigated to assess PAH exposure in Italy, by means of environmental-air monitoring (the 16 most relevant, according to the American Environmental Protection Agency, EPA) and biological monitoring (urinary 1-hydroxypyrene excretion). Our results show that PAH exposure in these workers is not higher than that observed in traffic policemen working in urban areas. Since dermal exposure has been suggested as a major determinant of the total PAH dose absorbed by road pavers from bitumen fumes, we assessed skin contamination by organic aromatic compounds and by sixteen PAH: in both groups, six pads were applied to each subject in different parts of the body, during the workshift. The results show that the dermal contamination in road pavers is higher than in ground construction operators and that cutaneous dose rate is higher than respiratory dose rate, whereas the amount of absorption the ratio is inverted.

[New biomarkers of exposure]. / Nuovi indicatori di esposizione.

In this paper we have defined the new biomarkers of exposure (NBE) as those biomarkers discovered in the last five years and, among previously validated biomarkers, also those applied in different ranges of doses or those determined in biological matrices which differ from matrices originally considered. We examined the results from the surveys carried out by the main Italian research units involved in biological monitoring, i.e. those from the Universities of Brescia, Milan, Naples, Padua, Parma, Pavia, Turin and Verona. The data were collected using a standardized model and included the following: type of element or organic compound, type of biomarker, analytical technique and method, their relationship with environmental monitoring data, their relationship with effect indicators or effects in general, improvement with respect to old biomarkers, reference values. Twenty two NBEs were identified: 14 elements and chemical compounds as such or as metabolites, 4 examples of mixtures, 3 of new matrices, one of speciation. Among the others, aspects such as interest in requiring NBE, quality assurance, availability, cost-benefit ratio were discussed. We conclude that development of this specific field of research appears to be a crucial point for future improvement in risk assessment and health surveillance procedures.

Difficult hernia repair in the elderly. A particular case.

A particular clinical case personally observed is described. On the basis of this case it is evaluated if it can be correct to implant a mesh in potentially contaminated areas, if preperitoneal repair is the best approach in recurrent or difficult hernia repair and if there are specific contraindications in operating elderly patients.

[European multicenter cross-sectional study on exposure to low doses of benzene]. / Studio trasversale multicentrico europeo su esposizione a basse dosi di benzene.

A cross-sectional multicenter european study has been carried out to evacuate the relations between exposure to low level of benzene and biological markers of internal dose (t,t-MA, S-PMA) and early biological effect (DNA-SSB). The research has shown significantly increased levels (adjusted for smoking habits) of the urinary excretion of t,t-MA, S-PMA and DNA-SSB in petrochemical workers (mean benzene level = 5,694 micrograms/m3) but not in filling station attendants, traffic police officers, and bus drivers compared to referent workers. Dose-response relations were detected between benzene air levels, t,t-MA, S-PMA and DNA-SSB in petrochemical workers, with significantly increased levels of DNA-SSB detected for benzene exposure levels in the range 391-1,800 micrograms/m3 (0.12-0.58 ppm).

[Assessment of exposure to polycyclic aromatic hydrocarbons during road paving]. / Valutazione dell'esposizione a idrocarburi policiclici aromatici nella stesura di asfalto.

Asphalt is a mixture of bitumen, (its fumes contain about 1% of polycyclic aromatic hydrocarbons, PAH), and mineral matter. 18 Workers were investigated during road paving to assess PAH exposure by environmental air-monitoring (the 16 most relevant, according to the American Environmental Protection Agency, EPA) and biological monitoring (urinary 1-hydroxypyrene excretion). Our results show that PAH exposure in these workers is not higher than that observed in traffic policemen working in urban areas.

[Evaluation of the dose of mercury in exposed and control subjects]. / Valutazione delle dosi di mercurio negli esposti e nei controlli.

OBJECTIVES: The aim of this paper was to analyse the concentrations of HgU and HgB in three different groups: 122 workers exposed, 18 workers formerly exposed and 196 subjects not occupationally or environmentally exposed to mercury. METHODS: All the subjects filled out a questionnaire concerning personal data, lifestyle, occupational or non-occupational exposure to Hg and medical history. The amalgam fillings area was measured by a standardised method. RESULTS: Urinary mercury excretion was significantly greater in the group of the exposed workers respect to the group of subjects not occupationally exposed (Median value of 8.3 micrograms/g creatinine and the 5 degrees and 95 degrees percentile respectively of 2.66 e 23.50 micrograms/g creatinine against Median value of 1.2 micrograms/g creatinine and the 5 degrees and 95 degrees percentile respectively of 0.18 and 5.42 micrograms/g creatinine). U-Hg in formerly exposed workers were comparable to U-Hg in non-occupationally exposed subjects, with a median value of 1.6 micrograms/g creatinine. B-Hg values were similar in the three groups: the median value was 3.1 micrograms/l in the non-occupationally exposed, 4.0 micrograms/l in the exposed workers and 3.9 micrograms/l in the past exposed. These value were not significantly different. Among the considered variables (amalgam fillings, fish consumption, age, sex, alcohol intake, chewing-gum and smoking) dental amalgam and fish consumption were significantly related with the Hg urinary excretion and the B-Hg levels. This is particularly true considering the subjects altogether: for the exposed workers, indeed, the occupational exposure was the most relevant variable. CONCLUSIONS: The results of the present research confirmed that the U-Hg excretion in non-occupationally exposed subjects is influenced by amalgam dental fillings. Furthermore, in our study Hg urinary excretion was significantly related with fish consumption. This fact can be explained, according to several recent experimental human and animal trials, considering that methylmercury contained in fish is partially converted, through breakage of the carbon-Hg bond, into Hg inorganic forms, which accumulate in the kidney and have a urinary excretion pathway.

[Evaluation of the neurotoxic and nephrotoxic effects following long-term exposure to metallic mercury in employed at a chlorine/sodium-hydroxide plant]. / Valutazione degli effetti neurotossici e nefrotossici conseguenti all'esposizione a lungo termine a mercurio metallico dei lavoratori addetti agli impianti Cloro-Soda.

OBJECTIVES: Within the frame work of a wide multicentre study, a sub-study was developed in order to explore the occurrence of early effects on the central nervous system, on the kidney and on the neuro-immune system in the workers of a chloro-alkali production plant exposed to metallic mercury at airborne concentration levels lower than 0.025 mg/m3 (TLV-TWA). They were compared to a control population of employees of the same huge petrochemical plant with different job that did not implicate exposure to mercury vapors. Specifically, the study aimed at revealing the occurrence of early effects on the central nervous system related with mercury exposure, as can be assessed through neurophysiological and neurobehavioral tests. METHODS: The excretion of urinary mercury was measured by atomic absorption spectrometry. The study of renal function was assessed by measurement of the urinary excretion of some high and low molecular weight protein markers (albumin, beta 2-microglobulin, retinol-binding protein, fibronectin, specific proximal tubule brush border antigens, N-acetyl-beta-D-glucosaminidase). The neurobehavioral status of the study subjects was assessed by means of several test parameters (Simple Reaction Time, Color Word Vigilance Test, Symbol Digit, Finger Tapping, Mood Scale of Kjellberg and Iwanowski, Subjective symptoms questionnaire (QSS), Luria Nebraska Motor Scale, Branches Alternate Movement Task and Tremometry). RESULTS: The values of urinary excretion averaged 12 +/- 8 micrograms Hg/g of creatinine for the exposed workers group (n = 38), while for the reference group (n = 34 cases) urinary excretion was statistically lower, averaging 4 +/- 6 micrograms Hg/g of creatinine. Neither the parameters selected for the assessment of renal functions, nor those chosen to probe the neurobehavioral status of the probands revealed statistically reliable differences between the group of exposed workers (length of exposure: range 1-34 years) and the control group. Nevertheless, some minor but still statistically reliable correlations were found between some neurobehavioral parameters and some demographic variables describing the whole group of tested workers, but not to the level of occupational exposure to mercury. CONCLUSIONS: The results of the study confirm the lack of toxic effects of clinical importance on the central nervous system and on the kidney for values of mercury urinary excretion lower than the suggested index of biological exposure (IBE) of 35 micrograms Hg/gram of creatinine.

Determination of hexafluoroisopropanol, a sevoflurane urinary metabolite, by 9-fluorenylmethyl chloroformate derivatization.

A reversed-phase HPLC method with fluorescence detection for the quantification of hexafluoroisopropanol (HFIP) in urine is presented. HFIP, a metabolite of the inhalation anesthetic sevoflurane, is excreted mainly in urine as glucuronic acid conjugate. After enzymatic hydrolysis of the glucuronate, primary amino groups of interferent urinary compounds are blocked by reaction with o-phthalic dicarboxaldehyde and 3-mercaptopropionic acid, followed by labeling of HFIP with 9-fluorenylmethyl chloroformate. The derivatization reaction proceeds in a water-acetonitrile (1:1) solution at room temperature with a borate buffer of pH 12.5 as a catalyst. A stable fluorescent derivative of HFIP is formed within 5 min. The HFIP-FMOC derivative is separated by reversed-phase chromatography with isocratic elution on an octadecyl silyl column (33x4.6 mm, 3 microm) and guard column (20x4.0 mm, 40 microm), at 35 degrees C, and detected by fluorescence detection at an excitation wavelength of 265 nm and an emission wavelength of 311 nm. The method detection limit is 40 pg, per 10-microl injection volume, corresponding to 16 microg/l of HFIP in urine. The among-series relative standard deviation is <6% at 200 microg/l (n=6). As a preliminary application, the method was used to detect HFIP concentration in the urine of two volunteers exposed for 3 h to an airborne concentration of sevoflurane in the order of 2 ppm.

Determination of monobromobimane derivatives of phenylmercapturic and benzylmercapturic acids in urine by high-performance liquid chromatography and fluorimetry.

A method was developed for the determination in human urine of S-phenylmercapturic (PMA) and S-benzylmercapturic (BMA) acids, metabolites respectively of benzene and toluene. PMA and BMA were determined, after alkaline hydrolysis, to give respectively thiophenol and benzylmercaptan, and coupling of the thiol-containing compounds with monobromobimane (MB), by reversed-phase HPLC on a diphenyl-silica bonded cartridge (100 x 4.6 mm I.D., 5 microm particle size) with fluorimetric detection. Wavelengths for excitation and emission were 375 and 480 nm, respectively. The recovery of PMA and BMA from spiked urines was >90% in the 10-500 microg/l range; the quantification limits were respectively 1 and 0.5 microg/l; day-to-day precision at 42 microg/l was C.V. <7%. The suitability of the proposed procedure for the biological monitoring of exposure to low-level airborne concentrations of benzene and toluene, was evaluated by analyzing the urinary excretion of PMA and BMA in subjects exposed to different sources of aromatic hydrocarbons, namely occupationally-unexposed referents (non-smokers, n=15; moderate smokers, n=8; mean number of cigarettes smoked per-day=17 cig/day) and non-smoker workers occupationally exposed to toluene in maintenance operations of rotogravure machines (non-smokers, n=17). Among referents, non-smokers showed values of PMA ranging from <1 to 4.6 microg/l and BMA from 1.0 to 10.4 microg/l; in smokers, PMA values ranging from 1.2 to 6.7 microg/l and BMA from 9.3 to 39.9 microg/l, were observed. In occupationally exposed non-smoker subjects, BMA median excretion value (23.6 microg/l) was higher than in non-smoker referents (3.5 microg/l) (P<0.001) and individual BMA values (y, microg/l) were associated and increased with airborne toluene concentration (x, mg/m3) according to the equation y=6.5+0.65x (r=0.69, P<0.01, n=17). The proposed analytical method appears to be a sensitive and specific tool for biological monitoring of low-level exposure to benzene and toluene mixtures in occupational and environmental toxicology laboratory.

Comparison between blood and urinary toluene as biomarkers of exposure to toluene.

OBJECTIVES: To compare blood toluene (TOL-B) and urinary toluene (TOL-U) as biomarkers of occupational exposure to toluene, and to set a suitable procedure for collection and handling of specimens. METHOD: An assay based on headspace solid-phase microextraction (SPME) was used both for the determination of toluene urine/air partition coefficient (lambdaurine/air) and for the biological monitoring of exposure to toluene in 31 workers (group A) and in 116 non-occupationally exposed subjects (group B). Environmental toluene (TOL-A) was sampled during the work shift (group A) or during the 24 h before specimen collection (group B). Blood and urine specimens were collected at the end of the shift (group A) or in the morning (group B) and toluene was measured. RESULTS: Toluene lambdaurine/air was 3.3 +/- 0.9. Based on the specimen/air partition coefficient, it was calculated that the vial in which the sample is collected had to be filled up to 85% of its volume with urine and 50% with blood in order to limit the loss of toluene in the air above the specimen to less than 5%. Environmental and biological monitoring of workers showed that the median personal exposure to toluene (TOL-A) during the work-shift was 80 mg/m3, the corresponding TOL-B was 82 microg/l and TOL-U was 13 microg/l. Personal exposure to toluene in environmentally exposed subjects was 0.05 mg/m3, TOL-B was 0.36 microg/l and TOL-U was 0.20 microg/l. A significant correlation (P < 0.05) was observed between TOL-B or TOL-U and TOL-A (Pearson's r = 0.782 and 0.754) in workers, but not in controls. A significant correlation was found between TOL-U and TOL-B both in workers and in controls (r = 0.845 and 0.681). CONCLUSION: The comparative evaluation of TOL-B and TOL-U showed that they can be considered to be equivalent biomarkers as regards their capacity to distinguish workers and controls and to correlate with exposure. However, considering that TOL-U does not require an invasive specimen collection, it appears to be a more convenient tool for the biological monitoring of exposure to toluene.