An extremely young massive clump forming by gravitational collapse in a primordial galaxy.

When cosmic star formation history reaches a peak (at about redshift z ≈ 2), galaxies vigorously fed by cosmic reservoirs are dominated by gas and contain massive star-forming clumps, which are thought to form by violent gravitational instabilities in highly turbulent gas-rich disks. However, a clump formation event has not yet been observed, and it is debated whether clumps can survive energetic feedback from young stars, and afterwards migrate inwards to form galaxy bulges. Here we report the spatially resolved spectroscopy of a bright off-nuclear emission line region in a galaxy at z = 1.987. Although this region dominates star formation in the galaxy disk, its stellar continuum remains undetected in deep imaging, revealing an extremely young (less than ten million years old) massive clump, forming through the gravitational collapse of more than one billion solar masses of gas. Gas consumption in this young clump is more than tenfold faster than in the host galaxy, displaying high star-formation efficiency during this phase, in agreement with our hydrodynamic simulations. The frequency of older clumps with similar masses, coupled with our initial estimate of their formation rate (about 2.5 per billion years), supports long lifetimes (about 500 million years), favouring models in which clumps survive feedback and grow the bulges of present-day galaxies.

False positive tardus-parvus waveforms after liver transplantation: a case of wide discrepancy between donor and recipient hepatic arteries mimicking anastomotic stenosis.

BACKGROUND: Parvus-tardus waveforms of the hepatic artery after liver transplantation usually indicate an arterial complication and severe impairment of hepatic arterial perfusion with a sensitivity of 91% and a specificity of 99.1%. Thus, it has been emphasized that detection of such waveforms should prompt emergency angiography. MATERIALS AND METHODS: Arterial reconstruction during a liver transplantation was successfully accomplished by an end-to-end anastomosis, performing a "flute-spout" widening of the anastomosis with a 7/0 prolene running suture between a small recipient proper hepatic artery and the donor common hepatic artery. RESULTS: On day 7 posttransplantation color Doppler ultrasonography revealed a parvus-tardus waveform pattern in the hepatic arterial flow. Computed tomographic (CT) angiography showed only a caliber discrepancy between the donor and recipient stumps, excluding an arterial stenosis or thrombosis. Since normal liver function persisted, the patient underwent routine follow-up. After 15 months the patient was alive and well; hepatic artery spectral waveforms were unchanged and liver functions were consistent with a mild hepatitis C virus (HCV) recurrence. CONCLUSIONS: This is a report of false positive tardus-parvus waveforms, due to a discrepancy between the donor and recipient arteries despite a wide anastomosis. Knowledge of technical reconstruction details may be helpful for correct interpretation of color Doppler findings. CT angiography should be considered before more invasive examinations.

Cost analysis of tumor downsizing for hepatocellular carcinoma liver transplant candidates.

We report the results of a prospective, intent-to-treat (ITT) trial on the costs of selective tumor downsizing (DS) before liver transplantation (LT) for patients affected with hepatocellular carcinoma (HCC). The trial started in January 1997 including adult patients with nodular-type HCC within and beyond the Milan criteria. Patients were downsized with transarterial chemoembolization (TACE), percutaneous ethanol injection (PEI) and/or radiofrequency ablation (RFA) according to clinical predictors. TACE and RFA were performed as inpatient procedures, while PEI was performed on an outpatient basis. Costs of DS were obtained according to the Tuscany Health Reimbursement Fee Catalog adjusted to yearly inflation rates from 1997 through 2005. Data analysis was performed at 1 year after the last enrollment of 198 patients, including 161 (81.3%) who were transplanted: 34 (17.2%) dropped out and 3 (1.5%) were still on the waiting list. One hundred and fifty-two patients (76.7%) underwent DS for a total of 201 procedures: 159 TACE, 39 PEI, and 3 RFA. Overall costs in Euros (euro) of waitlisting were 861,801.24 euro: 548,460 euro (63.7%) for pretransplantation evaluation; 197,994.84 euro (22.9%) for control visits and hospitalizations; and 115.346.4 euro (13.4%) for DS. Mean costs of DS were 758.58 euro +/- 270 euro per downstaged patient (747.53 euro +/- 257.1 euro Milan; 774.01 euro +/- 287.71 euro non-Milan); 582.85 euro +/- 398.87 euro per waitlisted patient (520.28 euro +/- 406.23 euro Milan; 520.28 +/- 364.48 euro non-Milan); and 716.4 euro per transplanted patient (580.67 euro Milan; 1026.76 euro non-Milan; +76.8%). A selective policy of tumor DS increased the costs of LT waitlisting by 13.4%, but due to higher dropout rates among non-Milan patients, the cost utility of DS was 76.8% higher in the Milan group.

Surveillance and rescue of pancreas grafts.

BACKGROUND: Technical failure rates are higher for pancreas allografts (PA) compared with other solid organs. Posttransplant surveillance and prompt availability of rescue teams with multidisciplinary expertise both contribute to improve this result. We herein report a single institution's experience with posttransplant surveillance and rescue of PA. METHODS: A retrospective survey was performed of a consecutive series of 177 whole organ pancreas transplants in 173 patients. Antithrombotic prophylaxis was used in all recipients and tailored on anticipated individual risk of thrombosis. During the first posttransplant week, all PA were monitored with daily Doppler ultrasonography. Surgical complications were defined as all adverse events requiring relaparotomy during the initial hospital stay or the first 3 posttransplant months. RESULTS: A total of 26 relaparotomies were performed in 25 patients (14.7%). One recipient needed two relaparotomies (0.6%). Graft rescue was attempted in patients without permanent parenchymal damage at repeat surgery and in 12 recipients diagnosed with nonocclusive vascular thrombosis. Overall 25 grafts (96.3%) were rescued and one was lost. One-year recipient and graft survivals in patients with versus without complications potentially leading to allograft loss were 92.6% and 63.0% versus 94.4% and 94.3%, respectively. Excluding complications for which graft rescue was not possible, 1-year graft survival rate increased to 78.7%. CONCLUSIONS: Close posttransplant surveillance can allow rescue of a relevant proportion of PA developing nonocclusive venous thrombosis or other surgical complications. Further improvement awaits better understanding of biological reasons for posttransplant complications jeopardizing PA survival and the development of more effective preventive measures.

A low frequency 1H-NMR external unit for the analysis of large foodstuff samples.

An inexpensive external unit that allows the use of a commercial high-resolution NMR spectrometer as a very low frequency instrument is described. The external unit is phase coherent, the pulse timing being given by the parent spectrometer. With the exception of the probe, the external unit does not contain any tuned elements. This permits easy change of frequency in the range 100 kHz-1 MHz. The external unit may be appropriately employed in food science where, in several cases, low frequency is desirable. An application to hen shell eggs at the frequency of 700 kHz is described.

Visceral leishmaniasis in a patient treated for polyarteritis nodosa.

We report a case of visceral leishmaniasis in a patient receiving steroids and cyclophosphamide for polyarteritis nodosa. The clinical presentation of leishmaniasis, with fever, pancitopenia and hypergammaglobulinemia may be confused with a reactivation of vasculitis or with other non-infectious conditions such as haematologic diseases. In endemic areas, the case of latent leishmaniasis must be considered and serology for Leishmania should be performed before starting immunosuppressive treatment.

Treatment of renovascular disease and of renovascular hypertension.

Treatment of occlusive lesions of renal arteries, defined as renovascular disease (RVD), is aimed both at preventing ischemic renal disease (IRD) and rescuing renal function through revascularization procedures, such as PTRA, endovascular stenting and surgical revascularization, as well as curing or improving hypertension in the presence of renovascular hypertension (RVH), i.e. hypertension caused by these vascular lesions. Preventive treatment of IRD is still an individual decision making process based on the type of renal lesions, degree of renal stenosis and progressive loss of renal mass as well as on immediate and late technical success of revascularization procedures together with their rate of complications. Rescue of renal function and-or prediction of the outcome of renal function after successful revascularization depends not only on the possibility of clarifying whether the decrease in renal function is a functioning-reversible phenomenon linked to renal hypoperfusion but also on the potential risk that the revascularization procedure may induce irreversible kidney damage. The rationale for treating RVH through revascularization procedures derives from the possibility of establishing a pathogenetic link between the occlusive lesions and hypertension, mainly through renal vein renin measurement and captopril renography and possibly their combination. Finally, medical treatment of hypertension is needed in patients who cannot undergo or refuse revascularization and whose blood pressure is not normalized by these procedures.

Determination of opiates in hair. Effects of extraction methods on recovery and on stability of analytes.

In order to evaluate (i) the recovery of extraction of opiates from authentic hair samples and (ii) the extent of hydrolysis of acetylated opiates (6-acetylmorphine, acetylcodeine) occurring during sample preparation, three different methods of extraction commonly used for opiates have been compared. To this purpose a sample consisting of a pool of hair collected from several heroin overdose cases has been submitted alternately to (A) digestion in 2 M NaOH at 80 degrees C for 1 h (n = 5), (B) incubation in 0.1 M HCl at 45 degrees C for 18 h (n = 5) and (C) incubation in methanol at 37 degrees C for 18 h (n = 5). After pH adjustment of the different incubation media to 7-8, analytes have been isolated by means of SPE using Bond Elut certify columns and derivatized with MSTFA. Analyses have been performed by either GC-MS in the selected ion monitoring mode or, omitting SPE, by radioimmunoassay. The extent of hydrolysis of 6-acetylmorphine to morphine and of acetylcodeine to codeine have been determined by submitting blank hair samples spiked with the acetylated analytes to the different extraction methods and measuring the amount of morphine and codeine formed. Both the recovery of extraction of the total morphine fraction (6-acetylmorphine + morphine) and the rate of hydrolysis of 6-acetylmorphine were found to be in the order: A > B > C. Similar results were obtained for the total codeine fraction (acetylcodeine + codeine). These results clearly indicate that: (i) the concentration of opiates measured in hair depends on the extraction method used; (ii) ratios between different analytes (e.g. 6-acetylmorphine vs. morphine) may reflect the rate of hydrolysis during sample preparation rather than different types of exposure to opiates.

Hair analysis for opiates, cocaine and metabolites. Evaluation of a method by interlaboratory comparison.

The aim of this study was to evaluate the performance of a technique for the simultaneous testing of opiates, cocaine and metabolites in hair by interlaboratory comparison. Sixteen forensic and clinical laboratories with different degrees of experience in hair analysis participated voluntarily in the study (no selection criteria were applied). The suggested analytical procedure, the one routinely used in our laboratory, consisted of incubation in HCl 0.1N (45 degrees C, overnight), solid phase extraction (with Bond Elut Certify) cartridges), derivatisation (trimethylsilyl (TMS) derivatives) and GC-MS analysis. Three different mixtures of finely cut (1 mm or less) hair were prepared using drug-users' and drug-free hair: one 'negative' sample (<0.1 ng/mg for morphine, 6-acetylmorphine (6AM), cocaine and benzoylecgonine (BE)), one 'low concentration' sample (between 0.5 and 2 ng/mg) and one 'high concentration' sample (>3 ng/mg). Accuracy and precision (CV% lower than 5.1, 9.9, 5.2, 3.8, 7.3 and 8.3% for morphine, 6AM, codeine, cocaine, BE, and methylecgonine (ME), respectively; range 0.5-5 ng/mg) of the method and homogeneity of the mixtures were evaluated in our laboratory by intraday (CV% lower than 12% for all analytes) and interday analyses (CV% lower than 17% for all analytes except 6AM, 25%). Participants in the study were grouped into: (1) laboratories (n = 6) obtaining the best qualitative and quantitative values, corresponding to those with long experience in hair analysis; (2) laboratories (n = 5) with no reported false positive and/or false negatives; (3) laboratories (n = 5) with one or more reported false positives/false negatives. The results obtained by the labs of the first group were used as reference values. The scatter of data was similar to those obtained in other published studies.

Simultaneous hair testing for opiates, cocaine, and metabolites by GC-MS: a survey of applicants for driving licenses with a history of drug use.

A sensitive GC-MS method for the simultaneous determination of opiates, cocaine, and metabolites in hair at a cut-off level of 0.1 ng/mg was adopted to assess past exposure to these drugs in applicants for driving licenses with a history of drug use. The sampling protocol consisted of collection of one hair (sample A, 5-cm length) and one urine sample. When hair and urine (EMIT Syva, cut-off levels: 0.3 mg/l for opiates, 0.15 mg/l for cocaine, GC-MS confirmation of positives) were both positive or negative the protocol was concluded. In the other cases, the assessment of 'current exposure' to drugs was carried out, in order to avoid seriated random urinalysis, by collecting a second hair sample (sample B) 6 weeks later and analysing the proximal 1-cm segment. Out of the 214 'A' hair samples analyzed, 14 (6.5%) tested positive for morphine and/or 6-acetylmorphine (6AM), and 26 (12%) for cocaine and/or benzoylecgonine (BE), whereas none of the samples tested positive for both drugs. Levels between 0.1 and 1 ng/mg of the single analytes were found in eight out of the 14 morphine-6AM positives (57%) and in 18 out of the 26 cocaine-BE positives (69%). The time course of positive cases showed a progressive decrease of morphine-6AM positives and a corresponding increase of cocaine-BE positives within the study period September 1995-February 1999. No cases with positive urine and negative hair were observed. Among the 40 positive cases, seven (four and three for opiates and cocaine, respectively) were found to be 'currently exposed to drug', four by urinalysis (three and one) and three by analysis of the hair sample B (1 and 2).

Role of interventional radiology in the management of vascular complications after liver transplantation.

The purpose of this study is to review the role of the percutaneous interventional procedures in the treatment of vascular complications after orthotopic liver transplantations (OLT). Vascular complications, such as arterial stenosis and venous thrombosis, which occur in approximately 1% to 10% of liver transplant patients, are associated with a higher risk of graft dysfunction. Percutaneous interventional procedures, including angioplasty, local thrombolysis, and embolization, are useful to manage these complications. A reduced blood loss and a low incidence of procedural complications allow for rapid recovery. Hepatic arterial and portal vein anastomotic stenosis can be treated effectively by means of balloon dilation; stenting has also been proposed, particularly for venous complications. Infusional local thrombolysis may be useful in venous thrombosis. Arteriovenous fistulas, occurring at the level of the anastomosis or after liver biopsy, require intraarterial embolization using microcoils or gelfoam. Timing of the intervention for the treatment of ischemic complications is of outmost importance to guarantee liver functional recovery and avoid irreversible parenchymal injuries. Other interventional procedures may be extremely useful to manage portal hypertension after OLT; for example, by creation of transjugular portosystemic shunts, or, in the case of associated hypersplenism, transarterial embolization of the splenic artery. Finally, in patients with recurrent hepatitis, the transjugular approach has been shown to be safe and effective for liver biopsy, whereas transarterial chemoembolization may be extremely useful to treat recurrent hepatocarcinoma.

Diagnosis and treatment of hepatic artery stenosis after orthotopic liver transplantation.

PURPOSE: The purpose of this study was to evaluate the accuracy of Multidetector Computed Tomographic Angiography (MDCTA) to detect hepatic artery (HA) stenosis after orthotopic liver transplantation (OLT) and the efficacy of treatment using percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS: Twenty-two consecutive patients with OLT underwent MDCTA for evaluation of HA, followed by digital subtraction angiography (DSA) (gold standard). Source images (Ax) were processed, obtaining multiplanar reformations (MPRs), maximum intensity projections (MIPs), and volume renderings (VRs). Images were evaluated to identify the following: (1) arterial depiction (celiac axis, anastomosis, and left [LHA] and right [RHA] HA), (2) detection of stenoses, and (3) grading of stenoses. Indications for PTA were set at MDCTA and DSA, and PTA was performed when appropriate. RESULTS: MDCTA depicted the celiac axis and anastomoses in all patients; LHA and RHA were visualized in 21 of 22 patients with Ax, MPRs, and MIPs, and in 17 of 22 with VRs. All reconstruction modalities enabled correct diagnosis of celiac (n = 3) and anastomotic stenoses (n = 14). Of 6 LHA and RHA stenoses, 4 (66.7%) were visualized with Ax, MPRs, and VRs, and 5 (83.3%) were visualized with MIPs. Stenosis was overestimated in 9 (39.1%) cases with VRs and in 3 (13%) with the other modalities. PTA was performed in 8 cases, with 1 case of arterial dissection requiring re-OLT. At a median follow-up of 28 months, the primary and secondary patency rates were 71.4% (5 of 7) and 85.7% (6 of 7), respectively. CONCLUSIONS: MDCTA and accurate postprocessing enable confident depiction of the arterial anatomy and detection of stenosis after OLT. PTA is safe and allows allograft saving, at least until another suitable donor becomes available.

Management of massive and persistent ascites and/or hydrothorax after liver transplantation.

PURPOSE: To describe the results of the treatment of eight liver transplantation (LT) patients subsequently developing large volumes of long-lasting ascites. PATIENTS AND METHODS: Between August 1996 and February 2003, 405 LTs were performed in 375 patients, eight (1.97%) of whom (six men and two women of mean age of 55.4 +/- 5.2 years) subsequently developed massive (> 500 mL/d) and persistent ascites and/or hydrothorax. All patients were HCV positive. The mean age of the liver donors was 66.8 +/- 21.9 years. All LTs were performed by replacement of the recipient retrohepatic vena cava. RESULTS: The eight patients displayed sinusoidal portal hypertension related to biopsy-proven recurrence of HCV infection. Mean wedged hepatic venous pressure was 14.9 +/- 5.1 mm Hg and mean portal vein/right atrial pressure gradient (PAPG) was 17.3 +/- 4.8 mm Hg. In two patients, the ascites appeared the day after LT; in the remaining six, ascites and/or hydrothorax appeared after 342.3 +/- 167.7 days. Seven patients with a mean PAPG of 18.4 +/- 3.9 mm Hg and a mean plasma/ascites albumin concentration gradient of 2.8 +/- 0.3 g/L were treated by means of a trans-jugular intrahepatic portosystemic shunt TIPS, and one (with a PAPG of 9 mm Hg and a plasma/ascites albumin concentration gradient of 1.38 g/L) by means of spleen arterial embolisation. After a mean follow-up of 558 +/- 147.2 days, the ascites and/or hydrothorax have resolved in five patients (62.5%), one (12.5%) has stable ascites not requiring paracentesis, and two (25%) have died of multiorgan failure. CONCLUSIONS: These data suggest the efficacy of the aggressive treatment of massive and persistent ascites and/or hydrothorax.

Rescue of kidney and pancreas grafts with complex vascular lesions.

BACKGROUND: The organ shortage mandates that grafts with complex vascular lesions be considered for graft rescue. METHODS: Surgical graft rescue was attempted in 8 patients bearing 8 kidneys and 2 pancreata that showed complex vascular lesions deemed not suitable for interventional radiology procedures. RESULTS: All procedures but 1 were performed under elective conditions. Seven grafts were repaired in situ, while cooling the organ through retrograde venous perfusion, and 3 kidneys were explanted, repaired extracorporeally, and retransplanted. All vascular reconstructions remain patent after a mean follow-up period of 3.3 years (+/-2.1 years). CONCLUSIONS: Careful patient selection, multidisciplinary evaluation, and personalized surgical technique may allow the rescue of kidney and pancreas grafts with complex vascular lesions that, otherwise, would be lost.

Hepatic resection after liver transplantation as a graft-saving procedure: indication criteria, timing and outcome.

BACKGROUND: Hepatic resection is uncommon after liver transplantation (LT), but can be a graft-saving procedure in selected cases. Herein we describe the criteria, outcome, and timing of this procedure in our series. METHODS: Between January 1996 and December 2002, 397 LTs were performed in 367 recipients, of whom 12 patients (3.2%) subsequently underwent liver graft resections because of ischemic-type biliary lesions (ITBLs) (n = 5, 41.6%), segmental hepatic artery thrombosis (S-HAT)(n = 3, 25%), recurrent hepatocellular carcinoma (HCC) (n = 2, 16.6%), liver abscess (n = 1, 8.3%), or liver trauma (n = 1, 8.3%). The patients were divided into group 1 (n = 3 all with S-HAT) who underwent early resections (within 3 months of LT), and group 2 (n = 9) who underwent late resections (after 3 months). The outcomes and postoperative mortality ratio (within 30 days) were compared. RESULTS: The resections consisted of four left lobectomies, three right hepatectomies, two extended right hepatectomies, one segmentectomy, one anterior trisegmentectomy, and one right lateral sectoriectomy. The perioperative mortality rate was 66.6% in group 1 (one case of myocardial infarction and one of sepsis), and 22% in group 2 (one case of sepsis and one of hepatic failure). CONCLUSIONS: Late resections in stable patients with damage confined to the graft yield good prognosis. Even major resections are feasible graft-saving procedures. In contrast, early hepatic resections in S-HAT are associated with a worse outcome. Retransplantation should be considered the first-choice option. Sepsis significantly affects the postsurgical course.

Surgical complications after liver transplantation.

AIM: The number of liver transplantations in Italy has steadily increased over the last 10 years as a result of the use of donors aged more than 60 years. The use of organs with a reduced functional reserve has been compensated for by improvements in immunosuppressive therapy, surgical techniques and the management of postoperative complications. This article describes the incidence and treatment of the main surgical complications after liver transplantation. METHODS: Between January 1996 and June 2003, 398 patients received 430 transplants at our Centre. Thirty-seven early relaparotomies were performed (8.6%), including 12 retransplantation (2.8%). The 1-, 3- and 5-year actuarial survival of the patients was 79.8%, 72.2% and 67.5%, and that of the grafts was 75.9%, 68% and 63.4%. Perioperative mortality was 10.5% (with no intraoperative deaths). RESULTS: The overall incidence of biliary complications was 31.6%, 9.1% of which were due to the removal of the Kehr tube. There were 42 (9.8%) anastomotic stenoses, 5 (1.2%) extra-anastomotic stenoses, 1 (0.2%) anastomotic leak, 5 (1.2%) extra-anastomotic leaks, and 19 (4.4%) ischemic-type biliary lesions. The overall incidence of vascular complications was 6.9%: 7 (1.6%) cases of hepatic artery thrombosis, 17 (4.0%) arterial stenoses, 1 (0.2%) arterial pseudoaneurysm, 4 (0.9%) cases of portal thromboses and 1 (0.2%) case of caval laminar thrombosis. Eight patients (1.9%) developed massive and persistent post-transplant ascites and/or hydrothorax. CONCLUSION: The use of donors aged more than 60 years makes it possible to maintain high standards of patient and graft survival that is not only due to the optimisation of immunosuppressive protocols, but also to improvements in surgical techniques, intensive care and the management of surgical complications.

Distribution of embutramide and mebezonium iodide in a suicide after tanax injection.

Tanax is a veterinary formulation for euthanasia comprising embutramide, mebezonium iodide and tetracaine. A 37-year-old female was found dead on her bed, with three empty used syringes and a bottle of Tanax beside her body. Three needle puncture marks were observed on the body. The aim of this study was to evaluate the distribution of embutramide and mebezonium iodide in different biological matrices (femoral and cardiac blood, liver, muscle and vitreous humor) using a chromatographic method for the simultaneous determination of the two drugs. A direct and sensitive liquid chromatography-tandem mass spectrometry method was developed in multiple reaction monitoring mode with positive ionization. Lidocaine was used as an internal standard. Limits of detection and quantitation of 0.01 and 0.05 mg/L, respectively, were reached for both compounds. Embutramide levels ranged from 2.74 mg/L in vitreous humor to 5.06 mg/L in femoral blood, while mebezonium iodide was found at widely differing concentrations (ranging from 2.80 mg/kg in muscle to 24.80 mg/kg in liver). The chromatographic method developed for this study provides a very simple and sensitive means for the simultaneous determination of embutramide and mebezonium iodide, the emetic concentrations of which were consistent with suicides reported in the literature.

The standardization of results on hair testing for drugs of abuse: An interlaboratory exercise in Lombardy Region, Italy.

Hair testing for drugs of abuse is performed in Lombardy by eleven analytical laboratories accredited for forensic purposes, the most frequent purposes being driving license regranting and workplace drug testing. Individuals undergoing hair testing for these purposes can choose the laboratory in which the analyses have to be carried out. The aim of our study was to perform an interlaboratory exercise in order to verify the level of standardization of hair testing for drugs of abuse in these accredited laboratories; nine out of the eleven laboratories participated in this exercise. Sixteen hair strands coming from different subjects were longitudinally divided in 3-4 aliquots and distributed to participating laboratories, which were requested to apply their routine methods. All the participants analyzed opiates (morphine and 6-acetylmorphine) and cocainics (cocaine and benzoylecgonine) while only six analyzed methadone and amphetamines (amphetamine, methamphetamine, MDMA, MDA and MDEA) and five Δ(9)-tetrahydrocannabinol (THC). The majority of the participants (seven labs) performed acidic hydrolysis to extract the drugs from the hair and analysis by GC-MS, while two labs used LC-MS/MS. Eight laboratories performed initial screening tests by Enzyme Multiplied Immunoassay Technique (EMIT), Enzyme-linked Immunosorbent Assay (ELISA) or Cloned Enzyme Donor Immunoassay (CEDIA). Results demonstrated a good qualitative performance for all the participants, since no false positive results were reported by any of them. Quantitative data were quite scattered, but less in samples with low concentrations of analytes than in those with higher concentrations. Results from this first regional interlaboratory exercise show that, on the one hand, individuals undergoing hair testing would have obtained the same qualitative results in any of the nine laboratories. On the other hand, the scatter in quantitative results could cause some inequalities if any interpretation of the data is required.