Mid-term clinical and radiographic outcome of metal-on-metal hip resurfacing through an anterolateral approach.

PURPOSE: The aim of this retrospective study was to evaluate the medium-term clinical and radiographic results of current generation metal-on-metal resurfacing prostheses performed through anterolateral approach. MATERIALS AND METHODS: Fifty-seven hips in 52 patients underwent resurfacing arthroplasty. Two patients died from unrelated causes, leaving 55 hips in 35 males (3 bilateral) and 15 females (2 bilateral), with a mean age at surgery of 56.2 years (range, 27-70 years). Clinical and radiographic assessment was carried out preoperatively and at follow-up in all the survived cases. The cumulative survival rate was determined according to the method of Kaplan-Meier. RESULTS: At a mean follow-up of 5.2 years (range, 1.8-9.1 years), 2 HRs of the same female patient were revised because of early loosening of the acetabular component. Deep venous thrombosis and transient femoral nerve palsy occurred both in 1 case. No specific complications of HR were observed. Average Harris hip score improved significantly from 59.8 points (range, 30.4-90.6) preoperatively to 93.7 points (range, 53-100) at the latest examination. Neck narrowing showed an average of 3.27%, but it never exceeded 10%. Nonprogressive acetabular radiolucencies and osteolysis were detected both in 2 hips. A high rate of patients (32, 60.4%) developed heterotopic ossifications, although low-grade in most cases (27, 84.4%). The cumulative survival rate at 9.1 years with revision for any reason as the end point was 93.0%. CONCLUSIONS: The early clinical and radiographic results of modern metal-on-metal hip resurfacing performed through an anterolateral approach are promising, but longer-term follow-up studies are necessary.

Solid state interactions in the La-Au-Mg system: phase equilibria, novel compounds and chemical bonding.

Gold intermetallic chemistry is very rich, covering different classes of compounds ranging from the Hume-Rothery to Zintl phases to polar intermetallics to quasicrystals. Au's relativistic effects are frequently mentioned as responsible for the peculiar structural and physical properties of its compounds, nonetheless the aspects of chemical bonding are far to be clearly understood. In this work, the La-Au-Mg system was targeted for the discovery of new gold intermetallics and their structural and chemical bonding characterization. Studies on solid state interactions resulted in the construction of a partial La-Au-Mg isothermal section at 400 °C. The high reactivity between the constituents is reflected by the formation of five intermetallic compounds in the concentration range of less than 50 at% of Au. A complete crystallographic study was conducted for four of them, namely La1.82Au3+xMg14.36-x (0 ≤ x ≤ 0.90, hP42-3.64-CeMg10.3), La3Au4-xMg12+x (0 ≤ x ≤ 0.75, hP38-Gd3Ru4Al12), LaAuMg2 (oS16-MgCuAl2) and LaAu1+xMg1-x (0 ≤ x ≤ 0.15, hP9-ZrNiAl). A unifying description based on the different stacking sequences of equal slabs along the c-axis is proposed for these intermetallics. Chemical bonding in LaAuMg2 was studied by following the position space approach and including relativistic effects. Among the peculiarities of this LaMg2Au auride, there are two-atomic La-Au bonds showing a classical polar covalent character and that form distorted hexagonal planar layers and multi-atomic bonds involving Mg species. One of these is interpreted as a Mg-Mg bond supported by the neighbouring La and Au atoms, explaining the Mg reduced oxidation state (close to +1) in this compound.

Long-term outcome of older patients with newly diagnosed de novo acute promyelocytic leukemia treated with ATRA plus anthracycline-based therapy.

Treatment outcome in older patients with acute promyelocytic leukemia (APL) is lower compared with younger patients, mainly because of a higher induction death rate and postremission non-relapse mortality (NRM). This prompted us to design a risk- and age-adapted protocol (Programa Español de Tratamientos en Hematología (PETHEMA)/HOVON LPA2005), with dose reduction of consolidation chemotherapy. Patients aged ⩾60 years reported to the PETHEMA registry and were treated with all-trans retinoic acid (ATRA) plus anthracycline-based regimens according to three consecutive PETHEMA trials that were included. We compared the long-term outcomes of the LPA2005 trial with the preceding PETHEMA trials using non-age-adapted schedules (LPA96&LPA99). From 1996 to 2012, 389 older patients were registered, of whom 268 patients (69%) were eligible. Causes of ineligibility were secondary APL (19%), and unfit for chemotherapy (11%). Median age was 67 years, without relevant differences between LPA2005 and LPA96&LPA99 cohorts. Overall, 216 patients (81%) achieved complete remission with no differences between trials. The 5-year NRM, cumulative incidence of relapse, disease-free survival and overall survival in the LPA2005 vs the LPA96&99 were 5 vs 18% (P=0.15), 7 vs 12% (P=0.23), 87 vs 69% (P=0.04) and 74 vs 60% (P=0.06). A less intensive front-line regimen with ATRA and anthracycline monochemotherapy resulted in improved outcomes in older APL patients.

The diagnostic value of cytohistological urine analysis and cytokeratin 20 in malignant and atypical urothelial cells.

INTRODUCTION: To determine the ability of cytohistology and cytokeratin 20 (CK 20) expression in malignant and atypical cells (AUC) from urine to serve as a diagnostic tool for assessing urothelial carcinoma (UC). METHODS: Diagnoses from 55 urine cytological samples from 55 patients were analyzed and correlated with subsequent biopsy findings. A total of 50 archived urine slides from patients that received a cytological diagnosis and histological follow-up were selected for immunostaining with monoclonal CK 20 antibodies and elaborated by Z-test for proportions. RESULTS: The majority of all positive or atypical smears (24; 89%) were confirmed through histological analysis. The majority of urinary cytological diagnoses reported as negative (15; 54%) were also confirmed through biopsies. The overall sensitivity, specificity, PPV, and NPV were 65%, 83%, 89%, and 54%, respectively. All 13 smears cytologically determined to contain malignant cells, with subsequent biopsies confirming UC, exhibited strong positive staining with the CK 20 antibody. All cases evaluated as benign both cytologically and histologically had negative CK 20 staining. Of the 15 AUC cases with lesions confirmed through biopsies, 11 (73%) had atypical cells that stained positive for CK 20. DISCUSSION: Our results demonstrate the diagnostic value of urinary cytology and confirm CK 20 as an adjunct marker for the diagnosis of UC and for the triage of AUC.

Delayed graft dislocation after thoracic aortic endovascular repair.

BACKGROUND: Endograft dislocation in thoracic aorta has not been widely studied. OBJECTIVES: The purpose of this study is to analyze the incidence and predisposing factor in a single centre experience after 117 procedures. METHOD: Between November 2000 and December 2011, all consecutive patients undergoing endovascular repair for descending thoracic or thoraco-abdominal aortic disease were identified. Follow-up imaging protocol included triple-phase CT-angiography at 1, 4, and 12 months, and annually thereafter. Migration was defined as proximal/ distal movements >10 mm relative to anatomical landmarks or any movement leading to symptoms or reintervention. RESULT: We identified 117 patients. Mean follow-up was 32 months (range, 1-144). Overall, five (4.3%) patients with thoracic EG dislocation were identified. Dislocation was classified as collapse/infolding in 3 cases and migration in 2. Mean delay of the dislocation was 12.7 months. Only one patient developed symptoms and required an additional endograft. In the group of dislocated endografts, mean age (53 ± 20 vs. 68 ± 15, P = .032) and the diameter of the aortic lesion were lower (4.1 cm ± 1.6 vs. 5.6 cm ± 1.8, P = .069), and the proximal landing zone at "zones 2 and 3" were more frequently used (5 vs. 65, P = 0.81). All but one patient with collapse/infolding are still alive and doing well at a mean follow-up of 80 months. CONCLUSION: Dislocation is an infrequent complication, but not so rare. Young age, small aortic diameter , and proximal sealing at the distal arch were the most important data associated with this complication.

Microstructure and in vitro degradation performance of Mg-Zn-Mn alloys for biomedical application.

Manganese and zinc were selected as alloying elements to develop a Mg-based ternary alloy for biomedical applications, taking into account the good biocompatibility of these metals. The microstructures of Mg-Zn-Mn alloys containing 0.5 or 1.0 mass% of manganese and 1.0 or 1.5 mass% of zinc were investigated by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. Their corrosion properties were assessed by means of potentiodynamic polarization and electrochemical impedance spectroscopy measurements performed in Ringer's physiological solution that simulates bodily fluids. All tested samples are two-phase alloys formed by a Mg-based matrix, consisting of a Mg-Zn-Mn solid solution, and a Mg-Zn binary phase. The electrochemical results show an improvement of the corrosion behavior of the investigated alloys with increasing Zn and Mn content. This is attributed to the formation of a partially protective Mg(OH)(2) surface film whose protective capabilities are increased by the alloying elements. The reduced influence of the Mg-Zn intermetallic compound on the corrosion rate of Mg-Zn-Mn alloys in the presence of a partially protective surface layer can be ascribed to an increasing resistance between the Mg-Zn-Mn solid solution and the second phase, thereby decreasing the effective driving force for microgalvanic corrosion. Owing to its highest corrosion protective ability, the Mg-1.5Zn-1Mn alloy is a promising candidate for the development of degradable implants, such as screws, plates, and rods.

[An unusual cause of chest pain in]. / Una causa insolita di dolore toracico in Chest Pain Unit: un caso di miocardite.

Myocarditis seems to be mostly caused by a viral infection or more rarely by a pharmacological hypersensitivity or by radiations exposure. Nevertheless, it is not so easy to know the ethiopathogenesis of the myocarditis, because mostly it is impossible to determine the infectious agent that causes the pathology even if it is isolated. The diagnosis could often remain uncertain, so a suspect of myocarditis has to be opportunely confirmed by specific serological and diagnostic investigations, in order to avoid the appearance of a dilated cardiomyopathy which is one of its principal sequences.

[A prompt diagnosis of Steinert's dystrophy in emergency unit]. / Una pronta diagnosi di distrofia miotonica di Steinert in Pronto Soccorso.

Atrial fibrillation is frequently observed in Fist Aid. A rare cause is myotonic dystrophy There are two forms: Steinert's dystrophy caused by a defect of a gene myotoninaprotein kinase and Promm secondary to a defect of a Zinc Finger Protein Gene Clinical manifestations are localized in skeletal and face muscles, vitreous body, sexual glands, endocrine system, smooth muscle, central nervous system and myocardium. Sometimes, in mild and unrecognized forms of this rare disease there are arrhythmias as atrial fibrillation. We report the clinical case of a 52 year-old man, with a suspect diagnosis of Steinert's dystrophy, admitted to the emergency room for a persistent atrial fibrillation. The patient begins oral anticoagulation therapy. The patient perform a transesophageal echocardiogram before the electrical cardioversion with reset to sinus rhythm. In conclusion, with improving the screening methods of patients with primary and secondary myopathies, it has been seen an increase of cases in which a cardiac involvement occurred before or after the onset of the neuromuscular disorders. One of the most frequent alterations is represented by atrial fibrillation, responsible for an increased risk of cerebral embolism, with absolute indication for oral anticoagulation therapy. The myopathy more frequently associated with atrial fibrillation, is myotonic dystrophy, although the risk of cerebral embolism in these patients does not appear to be higher than the general population. The present case report is a spur to perform the diagnosis of Steinert disease in cases admitted to an Emergency Room because of arrhytmias, because of the possibility to perform fast and reliable specific genetic tests. A similar praxis confers to these Units an even more diagnostic clinical role.

Bio-corrosion characterization of Mg-Zn-X (X = Ca, Mn, Si) alloys for biomedical applications.

The successful applications of magnesium-based alloys as biodegradable orthopedic implants are mainly inhibited due to their high degradation rates in physiological environment. This study examines the bio-corrosion behaviour of Mg-2Zn-0.2X (X = Ca, Mn, Si) alloys in Ringer's physiological solution that simulates bodily fluids, and compares it with that of AZ91 magnesium alloy. Potentiodynamic polarization and electrochemical impedance spectroscopy results showed a better corrosion behaviour of AZ91 alloy with respect to Mg-2Zn-0.2Ca and Mg-2Zn-0.2Si alloys. On the contrary, enhanced corrosion resistance was observed for Mg-2Zn-0.2Mn alloy compared to the AZ91 one: Mg-2Zn-0.2Mn alloy exhibited a four-fold increase in the polarization resistance than AZ91 alloy after 168 h exposure to the Ringer's physiological solution. The improved corrosion behaviour of the Mg-2Zn-0.2Mn alloy with respect to the AZ91 one can be ascribed to enhanced protective properties of the Mg(OH)(2) surface layer. The present study suggests the Mg-2Zn-0.2Mn alloy as a promising candidate for its applications in degradable orthopedic implants, and is worthwhile to further investigate the in vivo corrosion behaviour as well as assessed the mechanical properties of this alloy.

[Mantova cell factory: a model for skin regeneration]. / Mantova cell-factory: un modello di rigenerazione cutanea.

Chronic wounds, including venous and arteriosclerotic leg ulcers, diabetic foot ulcers, decubitus and trauma-induced wounds, represent a major problem in our society. Because the incidence of chronic wounds is high, the socioeconomic impact is considerable. The problem increases as the average age of the population increases and so the research into wound healing is continuously on the move. The aim of our research was to develop an autologous skin substitute and to verify its efficacy in closing chronic ulcers that do not respond to the currently available wound-healing treatments (topical therapy, antibiotics, surgical cleansing, external compression). Keratinocytes were obtained from the patients' foreskins. All medical procedures were undertaken with the approval of the ethics committee and with the patient's consent. In our survey we evaluated the possibility to grow autologous keratinocytes both with the ''feeder-layer'' method and on a type I collagen substrate. Using the first method, we obtained a two-dimensional strip composed of a few layers of normally arranged keratinocytes; it was, however, very fragile and this may affect the efficacy in clinical use. When cells were grown on an appropriately treated type I collagen substrate, we obtained more layers of normally arranged keratinocytes which were also differentiated into basal, spinous, granular and keratin layers. In addition to keratinocyte reproduction, we obtained reproduction of melanocytes in the correct basal position. The new skin substitute provides a new treatment option for chronic wounds that are refractory to conventional therapies. Adequate cytohistological and immunohistochemical analysis to evaluate the cells' correct morphology and phenotype is important in this technique.

[Characteristics, use and toxicity of fluorochemicals: review of the literature]. / Caratteristiche, uso e tossicità dei fluorurati: revisione della letteratura.

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are perfluorinated surfactants used to produce polymers and telomers whose carbon chain can be differently long. Polytetrafluoroethylene (PTFE), namely Teflon, is the chief fluoropolymer and it has been widely utilised over the last decades and all over the world. Indeed, its particular physical and chemical properties make it difficult to replace this substance in several industries (textile, paper, chemical, fire-fighting foam industry). Perfluoroalkyl-compounds may be considered ubiquitous and, in particular, it has been shown that PFOS may be concentrated in the food chain. Concerns about possible toxic effects of these chemicals date back to seventies, but only in 2000 the Environmental Protection Agency (EPA) stated PFOA and PFOS withdrawal to avoid environmental pollution. In 2002 the Organisation for Economic Co-operation and Development reported that these substances are bio-persistent, tend to accumulate in different tissues of living organisms and are toxic to mammalians. In 2006 EPA established that every PFOA emission will be eliminated not later than 2015. Actually, health effects of perfluoroalkyl-compounds on humans remain controversial, in spite of a number of experimental and epidemiological studies. Research focuses on possible endocrine disruption, thyroid and liver carcinogenicity, and development alteration. Our article reviews the main studies concerning PFOS and PFOA industrial and environmental toxicology.

Saliva as an analytical tool to measure occupational exposure to toluene.

OBJECTIVE: To describe a sensitive and rapid method for the determination of toluene in saliva. Biomonitoring of toluene exposure is commonly performed by determination of urinary hippuric acid, o-cresol or toluene itself. The analysis of blood toluene has been verified as another method for biomonitoring. However, drawing blood is invasive and can often not be performed at the workplace for hygienic reasons. Sampling of saliva may be non-invasive, easy to perform and a viable alternative for biomonitoring in the workplace. METHODS: We measured the solvent concentration in saliva specimens of 5 healthy volunteers studied in the laboratory and a group of 36 workers exposed to toluene in the synthetic leather industry. Saliva was collected into Salivette (Sarstedt, Germany) devices by sterile cotton rolls placed in the mouth and then squeezed into pre-weighted vials. Environmental toluene was collected for the duration of a work-shift by Radiello (FSM, Italy) passive samplers. Toluene in urine and saliva (head space analysis) and in environmental samples was measured by GC-MS. RESULTS: Environmental toluene levels ranged from 0.22 to 57.20 mg/m(3), while the concentrations of the solvent in saliva and urine ranged from 0.12 to 18.30 microg/L, and from 0.47 to 26.64 microg/L, respectively. The correlation coefficients (r) between biological and environmental levels of toluene were 0.77 and 0.93, respectively, for saliva and urine samples. CONCLUSION: This preliminary study suggests that saliva may offer many advantages over 'classical' biological fluids such as blood as it is readily accessible and collectible: therefore saliva toluene may be considered as a possible biomarker of exposure to toluene.

Tissue engineering: chondrocyte cultures on type I collagen support. Cytohistological and immunohistochemical study.

Cartilaginous tissue has limited capacity for regeneration after damage, since the natural repair process leads to the formation of fibrocartilaginous tissue which does not have the resistance and capability of deformation under load, typical of hyaline cartilage which covers the articular surfaces. The possibility of transplanting human chondrocytes for cartilage reconstruction has been demonstrated in orthopaedics. The scope of our study was to evaluate the possibility of cultivating and expanding human chondrocytes seeded on a pure equine type I collagen support. Human articular cartilaginous cells multiplied and grew on a type I collagen substrate with production of extracellular matrix. This chondrocyte culture showed a correct morphology and phenotype as shown by alcian-PAS staining to indicate the presence of mucopolysaccharides and by immunohistochemical methods to identify type II collagen. The use of scaffolds may lead to improvement in the surgical technique, by making it possible to hold the cells physically in the area to be repaired and by allowing optimum spatial adaptation inside injuries of all shapes.

[Recent prevention strategies and occupational risk analysis: Control Banding and Sobane]. / Recenti strategie per la prevenzione e l'analisi dei rischi in ambito occupazionale: Control banding e Sobane.

Employers are responsible for the prevention of risks and must provide for the safety and health of their workers. They are obliged to apply the general principles of prevention: to avoid, where possible, any risk; to characterize and hence to estimate residual risks; to eliminate risks at the source; to adjust jobs to the needs of workers and not workers to the jobs. When we pass to the practical performance of these shared principles we introduce many problems: problems concerning terminology; problems in estimating the nature of the risks that are faced; coordination problems between the subjects that preside over prevention; problems arising from the different typology of the companies investigated In order to answer these questions the "Industrial Hygienists" have long since created various strategies for the prevention and control of risks. Among different models the methods Control Banding and Sobane-Deparis are undoubtedly the most promising. Control Banding is designed to assist especially Small and Medium Enterprises in complying with the chemical safety regulations, the scheme uses the R phrases that in Europe must be assigned to potentially harmful chemicals by the manufacturer of the chemical. R phrases describe the most important harmful effects of a chemical and have been adopted in many non European countries also. The combination of the hazard classification of the chemical and assessment of the exposure potential will allow understanding of the level of risk thus leading the person carrying out the assessment to an appropriate control method. Occupational hygienists with experience of assessing occupational exposure to chemicals agreed parameters that could be used to give reasonable indications of exposure potential. One of them is quantity being used and three categories--small, medium and large--are defined. The likelihood of the chemical becoming airborne has been addressed by defining solids according to levels of dustiness and liquids according to volatility. A simple graph that uses the boiling point of the chemical and the process operating temperature assigns the chemical a high, medium or low volatility rating. The user now has enough information to identify the control approach required to adequately reduce exposures to the chemical Occupational hygienists agreed on three broad control approaches: General Ventilation; Engineering Control; Containment. However it is recognised that in some cases specialist advice will be needed. The user takes the hazard group, quantity and level of dustiness/volatility and matches them to a control approach using a simple table. The controls are described in control guidance sheets, which comprise both general information and, for commonly performed tasks, more specific advice. The second section of the document describes a risk-prevention strategy, called SOBANE, in four levels. These four levels are: screening, where the risk factors are detected by the workers and their management, and obvious solutions are implemented; observation, where the remaining problems are studied in more detail, one by one, and the reasons and the solutions are discussed in detail; analysis, where, when necessary, an occupational health (OH) practitioner is called upon to carry out appropriate measurements to develop specific solutions; expertise, where, in very sophisticated and rare cases, the assistance of an expert is called upon to solve a particular problem. The method for the participatory screening of the risks, Deparis, is proposed for the first level screening of the SOBANE strategy. The aim of Sobane strategy is to make risk prevention faster, more cost effective, and more effective in coordinating the contributions of the workers themselves, their management, the internal and external OH practitioners and the experts.

[The significance of enviromental and biological monitoring in workers employed in service stations after the elimitation of tetraethyl lead from gasoline]. / Il significato del monitoraggio ambientale e biologico nei lavoratori addetti alle stazioni di servizio dopo la eliminazione del piombo tetraetile dalle benzine.

The chemical risk in service stations may be due to toxic compounds present in fuel (particularly benzene and additives) and to the emission of exhausts and fine particulate from vehicles. Owing to the elimination of lead (Pb) from fuel and to the necessity of lowering CO emission, several oxygenated additives have been added to fuel, in particular methyl-tert-butyl-ether (MTBE), whose toxic properties are at present under investigation. The introduction of reformulated gasoline (RFG) and the use of catalytic converters (with possible release of platinum (Pt) in the environment) may have modified the risks for workers employed in service stations. The paper shows data collected from 26 subjects (divided into three specific tasks, namely: fuel dispenser, "self-service" attendant and controller, and cashier) to estimate the actual chemical risk and to compare it with the previous data taken from literature. For this purpose, besides performing the usual medical surveillance, we measured the environmental concentrations of benzene, MTBE and formaldehyde, the urinary levels of benzene metabolites S-phenylmercapturic acid (S-PMA) and t,t-muconic acid (MA) and of unmodified MTBE, and the blood concentrations of Pb and Pt for each subject. Mean values of these compounds were, respectively: 38.81 microg/m3; 174.04 microg/m3; 10.38 microg/m3; 2.36 microg/g creatinine; 96.57 microg/g creatinine; 1.41 microg/L; 7.00 microg/100 mL; 0.0738 ng/ml. The above values were much lower than the corresponding limit values reported by ACGIH and DFG. In particular, after the introduction of vapour recycle systems and the widespread use of "self-service" systems, airborne benzene concentration dropped from 300/400 microg/m3 to lower than 100 microg/m3, without noticeable increasing of exposure to formaldehyde. The disappearing of Pb from gasoline leads to a progressive lowering of its blood levels, while the possible risks due to the very low amounts of Pt released from catalytic converters have still to be defined exactly. Taken all in all, our results seem to indicate that, after the elimination of tetraethyl lead, the chemical risk for workers employed in service stations is now lower than in the past.

[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.

[Excretion kinetics of phenylhydroxyethyl mercapturic acids (PHEMAs), ethanol consumption, and chronic exposure to styrene: preliminary data on humans]. / Cinetica di escrezione degli acidi fenilidrossietilmercapturici (PHEMAs), consumo di etanolo ed esposizione cronica a stirene: dati preliminari sull'uomo.

Styrene (S) is a widely used aromatic hydrocarbon, responsible for several adverse effects. In humans, the metabolism of S is well characterized: besides the major metabolites (mandelic and phenylglyoxylic acid), a minor metabolic pathway leads to phenylhydroxyethyl mercapturic acids (PHEMAs) [N-acetyl-S-(1-phenyl-2-hydroxyethyl)-L-cysteine (M1) and N-acetyl-S-(2-phenyl-2-hydroxyethyl)-L-cysteine (M2)], that are potentially useful for biomonitoring purposes. A pilot study on a volunteer exposed under controlled conditions to S, with or without ethanol administration, allowed us to characterize the excretion profile of PHEMAs and the ethanol-induced interference on PHEMAs metabolic pathway. We further considered a group of 9 workers exposed to S during the working week to determine the confounding role of chronic exposure. Our results confirm the wide interindividual variability of both the biotransformation rate of S into PHEMAs and of the excretion rate of these metabolites. Moreover, both the above parameters changed during the working week, suggesting the existence of a large intraindividual variability as a consequence of the exposure to S and to other solvents. As a practical rule, the data indicate that it is necessary to collect samples at the beginning of the working week when studies on the correlation between genotype and phenotype are carried out. Finally, the results emphasise the importance of excluding an even extemporary ethanol assumption when practicing a biological monitoring programme based on the determination of urinary PHEMAs.

[Biological monitoring of occupational exposure to desflurane]. / Monitoraggio biologico dell'esposizione occupazionale a desflurane.

In these last years Desflurane (D) has become used, alone or in combination with nitrous oxide, in surgical procedures. Occupational exposed groups include anesthesiologists, other physicians, (e.g. surgeons) and operating room nurses. Desflurane is a halogenated methylethylether which is administered by inhalation. Desflurane is halogenated exclusively with fluorine. The blood/gas partition coefficient of Desflurane is 0.42. Changes in the clinical effects of Desflurane rapidly follow changes in the inspired concentration. Studies in man indicate that Desflurane washes into the body rapidly. It also washes out of the body rapidly, allowing flexibility in adjustment of the depth of anaesthesia. Desflurane is eliminated via the lungs, undergoing only minimal metabolism (0.02%). In order to investigate the role of urinary D as an indicator of occupational exposure to Desflurane (CI, ppm), CI was measured in 21 members of operating room staffs. For the measurement of environmental concentration of Desflurane (CI), the ambient air was sampled using personal passive dosimeters. The analyte was desorbed by a water-methanol mixture and was analysed by means a gas chromatograph--mass spectrometer (GC-MSD) and headspace technique. The biological monitoring of exposed workers was conducted by determining the concentration of Desflurane in urine (Cu, microgram/L). Urine concentrations of Desflurane were determined by headspace analysis using GC-MSD. Significant correlations were found between the environmental Desflurane concentration and the urinary concentrations. The correlation between CI (ppm) and Cu (microgram/L) was: Log D (Cu, microgram/L) = .191 + .922 * LogCI; r = .916 On the basis of the equation it was possible to establish tentatively the biological limit values corresponding to the respective occupational exposure limit values proposed for Desflurane.