Search for Gamma-Ray Spectral Lines from Dark Matter Annihilation up to 100 TeV toward the Galactic Center with MAGIC.

Linelike features in TeV γ rays constitute a "smoking gun" for TeV-scale particle dark matter and new physics. Probing the Galactic Center region with ground-based Cherenkov telescopes enables the search for TeV spectral features in immediate association with a dense dark matter reservoir at a sensitivity out of reach for satellite γ-ray detectors, and direct detection and collider experiments. We report on 223 hours of observations of the Galactic Center region with the MAGIC stereoscopic telescope system reaching γ-ray energies up to 100 TeV. We improved the sensitivity to spectral lines at high energies using large-zenith-angle observations and a novel background modeling method within a maximum-likelihood analysis in the energy domain. No linelike spectral feature is found in our analysis. Therefore, we constrain the cross section for dark matter annihilation into two photons to ⟨σv⟩≲5×10^{-28} cm^{3} s^{-1} at 1 TeV and ⟨σv⟩≲1×10^{-25} cm^{3} s^{-1} at 100 TeV, achieving the best limits to date for a dark matter mass above 20 TeV and a cuspy dark matter profile at the Galactic Center. Finally, we use the derived limits for both cuspy and cored dark matter profiles to constrain supersymmetric wino models.

Observation of Massless and Massive Collective Excitations with Faraday Patterns in a Two-Component Superfluid.

We report on the experimental measurement of the dispersion relation of the density and spin collective excitation modes in an elongated two-component superfluid of ultracold bosonic atoms. Our parametric spectroscopic technique is based on the external modulation of the transverse confinement frequency, leading to the formation of density and spin Faraday waves. We show that the application of a coherent coupling between the two components reduces the phase symmetry and gives a finite mass to the spin modes.

Allergic rhinitis and COVID-19: friends or foes?

Summary: Allergic rhinitis (AR) is a common disease affecting up to 40% of the general population worldwide. In the Coronavirus 2019 (COVID-19) pandemic era, many observational studies analysing the effect of asthma and chronic obstructive pulmonary disease on the risk of developing COVID-19 were conducted, while data on AR are limited.In this paper, we review the risk of developing SARS-Cov-2 infection carried by AR patients, the outcomes of those with COVID-19 disease, and the COVID-19 influence on the allergic and nasal symptoms and the psychological status of AR patients, in both adult and paediatric populations.AR patients seem to be protected from COVID 19 infection. Even if data about the influence of AR on the severity of COVID-19 disease are still not conclusive, it seems that being an AR patient does not increase the risk of poor COVID-19 prognoses. The clinical manifestation of AR can be distinguished by COVID-19 symptoms. Treating AR adequately is also strongly recommended, especially during pandemic.

Does musical interaction in a jazz duet modulate peripersonal space?

Researchers have widely studied peripersonal space (the space within reach) in the last 20 years with a focus on its plasticity following the use of tools and, more recently, social interactions. Ensemble music is a sophisticated joint action that is typically explored in its temporal rather than spatial dimensions, even within embodied approaches. We, therefore, devised a new paradigm in which two musicians could perform a jazz standard either in a cooperative (correct harmony) or uncooperative (incorrect harmony) condition, under the hypothesis that their peripersonal spaces are modulated by the interaction. We exploited a well-established audio-tactile integration task as a proxy for such a space. After the performances, we measured reaction times to tactile stimuli on the subjects' right hand and auditory stimuli delivered at two different distances, (next to the subject and next to the partner). Considering previous literature's evidence that integration of two different stimuli (e.g. a tactile and an auditory stimulus) is faster in near space compared to far space, we predicted that a cooperative interaction would have extended the peripersonal space of the musicians towards their partner, facilitating reaction times to bimodal stimuli in both spaces. Surprisingly, we obtained complementary results in terms of an increase of reaction times to tactile-auditory near stimuli, but only following the uncooperative condition. We interpret this finding as a suppression of the subject's peripersonal space or as a withdrawal from the uncooperative partner. Subjective reports and correlations between these reports and reaction times comply with that interpretation. Finally, we determined an overall better multisensory integration competence in musicians compared to non-musicians tested in the same task.

Bounds on Lorentz Invariance Violation from MAGIC Observation of GRB 190114C.

On January 14, 2019, the Major Atmospheric Gamma Imaging Cherenkov telescopes detected GRB 190114C above 0.2 TeV, recording the most energetic photons ever observed from a gamma-ray burst. We use this unique observation to probe an energy dependence of the speed of light in vacuo for photons as predicted by several quantum gravity models. Based on a set of assumptions on the possible intrinsic spectral and temporal evolution, we obtain competitive lower limits on the quadratic leading order of speed of light modification.

Disease trends over time and CD4+CCR5+ T-cells expansion predict carotid atherosclerosis development in patients with systemic lupus erythematosus.

BACKGROUND AND AIM: Patients with Systemic Lupus Erythematosus (SLE) present increased cardiovascular mortality compared to the general population. Few studies have assessed the long-term development and progression of carotid atherosclerotic plaque in SLE patients. Our aim was to investigate the association of clinical and laboratory markers of disease activity and classical cardiovascular risk factors (CVRF) with carotid atherosclerosis development in SLE patients in a prospective 5-year study. METHODS AND RESULTS: Clinical history and information on principal CVRFs were collected at baseline and after 5 years in 40 SLE patients (36 women, mean age 42 ± 9 years; 14.4 ± 7 years of mean disease duration) and 50 age-matched controls. Carotid Doppler ultrasonography was employed to quantify the atherosclerotic burden at baseline and at follow up. Clinimetrics were applied to assess SLE activity over time (SLEDAI). The association between basal circulating T cell subsets (including CD4+CCR5+; CD4+CXCR3+; CD4+HLADR+; CD4+CD45RA+RO-, CD4+CD45RO+RA- and their subsets) and atherosclerosis development was evaluated. During the 5-year follow up, 32% of SLE patients, developed carotid atherosclerosis compared to 4% of controls. Furthermore, considering SLEDAI changes over time, patients within the highest tertile were those with increased incidence of carotid atherosclerosis independently of CVRF. In addition, increased levels of CD4+CCR5+ T cells were independently associated with the development of carotid atherosclerosis in SLE patients. CONCLUSION: Serial clinical evaluations over time, rather than a single point estimation of disease activity or CVRF burden, are required to define the risk of carotid atherosclerosis development in SLE patients. Specific T cell subsets are associated with long-term atherosclerotic progression and may further be of help in predicting vascular disease progression.

Histamine release positive test associates with disease remission in chronic spontaneous urticaria: a proof-of-concept study.

SUMMARY: Background. Histamine release (HR) test has previously been shown to predict the presence of endogenous histamine-releasing factors in chronic spontaneous urticaria (CSU). Objectives and methods. Twenty CSU patients unresponsive to antihistamine treatment were enrolled in order to evaluate the correlations between HR test results and demographic features, quality of life, disease activity, clinical course, and autologous serum and plasma skin tests (ASST and APST). Results. All patients with positive HR test (9/9, 100%) had a more severe disease activity at onset (urticaria activity score, UAS > 2) when compared to negative HR test patients (5/11; p = 0.04). Quality of life questionnaire's results were not substantially different between HR positive and negative subgroups at baseline (p > 0.05), and results of HR test and ASST/APST did not co-segregate (p > 0.05). After 12 months, patients with a positive HR test had a significant reduction of disease activity (p = 0.003) whereas patients with a negative HR test did not (p > 0.05), leading to disease remission and antihistamine treatment withdrawal in 67% (6/9) of positive HR test patients versus 18% (2/11) of negative HR test patients (p = 0.027). Conclusions. Positive HR test may predict spontaneous CSU remission at 12 months.

IgG4-related disease in Italy: clinical features and outcomes of a large cohort of patients.

OBJECTIVES: To describe the clinical features, treatment response, and follow-up of a large cohort of Italian patients with immunoglobulin (Ig)G4-related disease (IgG4-RD) referred to a single tertiary care centre. METHOD: Clinical, laboratory, histological, and imaging features were retrospectively reviewed. IgG4-RD was classified as 'definite' or 'possible' according to international consensus guidelines and comprehensive diagnostic criteria for IgG4-RD. Disease activity was assessed by means of the IgG4-RD Responder Index (IgG4-RD RI). RESULTS: Forty-one patients (15 females, 26 males) were included in this study: 26 with 'definite' IgG4-RD and 15 with 'possible' IgG4-RD. The median age at diagnosis was 62 years. The median follow-up was 36 months (IQR 24-51). A history of atopy was present in 30% of patients. The pancreas, retroperitoneum, and major salivary glands were the most frequently involved organs. Serum IgG4 levels were elevated in 68% of cases. Thirty-six patients were initially treated with glucocorticoids (GCs) to induce remission. IgG4-RD RI decreased from a median of 7.8 at baseline to 2.9 after 1 month of therapy. Relapse occurred in 19/41 patients (46%) and required additional immunosuppressive drugs to maintain long-term remission. Multiple flares occurred in a minority of patients. A single case of orbital pseudotumour did not respond to medical therapy and underwent surgical debulking. CONCLUSIONS: IgG4-RD is an elusive inflammatory disease to be considered in the differential diagnosis of isolated or multiple tumefactive lesions. Long-term disease control can be achieved with corticosteroids and immunosuppressive drugs in the majority of cases.

Antimutagenicity and antigenotoxicity of Aloe arborescens Miller and Aloe barbadensis Miller in Aspergillus nidulans and Wistar rats.

Medicinal plants such as Aloe arborescens Miller and Aloe barbadensis Miller are used by the general population to treat various diseases. Therefore, the aim of this study was to evaluate the antimutagenicity of these two species using a methG1 system in Aspergillus nidulans and the comet assay in rats. The animals were treated with the plants at concentrations of 360 and 720 mg/kg body weight (1 and 2, respectively) by gavage for 14 days, followed by the administration of etoposide on treatment day 8. Blood samples were prepared for analysis of DNA damage. For the test in A. nidulans, the biA1methG1 lineage conidia were treated for 4 h with both plant species at concentrations of 4 and 8% (w/v). Then, they were washed and plated on a selective medium for frequency analysis of survival and mutation. The results of the comet assay showed that both plants were antigenotoxic compared to etoposide, which was not a typical response of methG1 systems, where only the highest concentration of plant extracts usually exhibit beneficial effects. This study demonstrates the potential antigenotoxicity and antimutagenicity of the Aloe plants tested and, therefore, supports their use as a form of preventive therapy and for health maintenance by the population.

Patients with breakthrough reactions to iodinated contrast media have low incidence of positive skin tests.

BACKGROUND: The term "breakthrough reactions" designates repeated hypersensitivity reactions to iodinated contrast media (ICM) despite premedication with glucocorticoids and antihistamines. We aimed to retrospectively evaluate the rate of positive skin test (STs) in our cohort of patients with previous breakthrough reactions to different ICMs. METHODS: A series of 35 patients, who experienced at least one breakthrough reaction to ICM and who underwent STs within 6 months from the reaction were studied, and results were compared to a control group of patients with a first hypersensitivity reaction occurred without premedication. Skin prick tests (SPT), intradermal tests (IDT) and patch tests (PT) at different dilutions, with a set of three to four ICM were performed. RESULTS: Of the 35 patients with prior breakthrough reactions, 57% had an immediate reaction (IR) and 43% had a non-immediate reaction (NIR). Patients who experienced the first hypersensitivity IR or NIR, later had one or more breakthrough IR or NIR, respectively. Overall, 29% (10/35) of patients with prior breakthrough reactions resulted positive to STs compared to 57% (16/28) of the control group (p < 0.05). No significant difference in allergy history, age, sex, other clinical / demographic features nor chronic use of ACE-inhibitor, beta-blockers or NSAIDs was observed. CONCLUSION: This preliminary finding suggests that patients with prior breakthrough reactions have significantly lower immunologically proven ICM reactions (positive STs) if compared to non-breakthrough patients. According to that, a considerable number of breakthrough reactions seems to be non-allergic hypersensitivity reactions or reactions which could be mostly prevented by a proper, well-timed skin testing. Larger prospective studies are needed to confirm these results, with a more careful analysis of patients' risk factors, a laboratory assessment that includes an in vitro allergy diagnostics, and hopefully a drug provocation test for selected cases.

Efficacy and safety of biological agents in adult-onset Still's disease.

OBJECTIVES: To describe the efficacy and safety of different biological agents in a large cohort of 20 patients with adult-onset Still's disease (AOSD). METHOD: We retrospectively evaluated 20 patients with severe or refractory AOSD treated with at least one biological agent (anakinra, etanercept, tocilizumab, and adalimumab), followed up for at least 12 months at our Institution. We collected and analysed data on the disease course, treatment outcome, and adverse effects, and compared our data with other published series. RESULTS: The median duration of follow-up was 5 years. In 12 patients a single biological drug induced a clinical response. In eight patients the biological agent that was first administered proved ineffective, and a switch to a different biologic was necessary. In three patients a third biologic was necessary to achieve disease control. The biologics eventually determined a clinical response in all patients. Patients with systemic disease showed better responses than patients with chronic articular disease (p < 0.05). Biological agents allowed either the withdrawal or the tapering of corticosteroid therapy (p < 0.0001) and of disease-modifying anti-rheumatic agents (DMARDs; p < 0.05). Three patients experienced herpes zoster reactivation. CONCLUSIONS: This is the longest follow-up of a cohort of AOSD patients treated with biological agents. Our data show that biologics are safe and generally effective in the long-term management of AOSD, particularly in cases with systemic disease, and suggest that a clinical response can be obtained in almost all AOSD patients, although a switch to drugs with a different mechanism of action may be necessary.

Cardiovascular manifestations of Erdheim-Chester disease.

Erdheim-Chester disease (ECD) is a rare inflammatory disorder of unknown etiology, characterised by diffuse organ infiltration of CD68-positive, CD1a-negative, S100-low/negative foamy histiocytes. It is a non-Langerhans cell histiocytosis which invariably involves bones (96% of cases). Extraskeletal involvement is observed in about 50% of cases. Cardiovascular involvement affects more than 20% of patients and associates with poor prognosis, conferring a reduced response to treatment. Frequent findings are pericardial effusion (24% of patients), "coated aorta", a perivascular circumferential thickening of the aorta, and pericardial thickening. Other typical features include right atrial mass with pseudo-tumoural appearance and histiocytes' infiltration of right atrial walls, atrioventricular sulcus and interatrial septum. After the recent introduction of cardiac cine MRI in the clinical assessment of patients affected by ECD, a growing body of case reports and retrospective data showed that cardiovascular involvement is present more frequently than previously thought and that it is relatively often asymptomatic. Hence, clinicians should systematically screen ECD patients for occult cardiovascular involvement by means of highly sensitive imaging tools. Despite these recent novelties, comprehensive literature reviews focusing on ECD cardiovascular involvement and its imaging assessment in the last decade are lacking.

Proposal of a skin tests based approach for the prevention of recurrent hypersensitivity reactions to iodinated contrast media.

The purpose of the present work is to evaluate the efficacy of an approach that combines clinical history, skin tests results, and premedication, in preventing recurrent hypersensitivity reactions to iodinated contrast media (ICM). Skin Prick tests, Intradermal tests, and Patch tests were performed in 36 patients with a previous reaction to ICM. All patients underwent a second contrast enhanced radiological procedure with an alternative ICM selected on the basis of the proposed approach. After alternative ICM re-injection, only one patient presented a mild NIR. The proposed algorithm, validated in clinical settings where repeated radiological exams are needed, offers a safe and practical approach for protecting patients from recurrent hypersensitivity reactions to ICM.

Antimutagenic and radioprotective activities of beta-carotene against the biological effects of iodine-131 radiopharmaceutical in Wistar rats.

Radioactive iodine-131 (131I) is used in the treatment and diagnosis of thyroid gland injuries. However, because it emits ionizing radiation, it causes harmful effects to cells. Given that beta-carotene (BC) has antioxidant and antigenotoxic properties, this study aimed to investigate its radioprotective and antimutagenic activity in relation to 131I at the dose that is used to treat hyperthyroidism using a test system of bone marrow cells from Wistar rats (Rattus norvegicus). The doses were 0.2 mL of 8 mg BC/mL corn oil and 25 µCi 131I per 100 g body weight, and they were given via gavage in acute and subchronic treatments. Treatment groups included simultaneous, pre-treatment, post-treatment, and continuous treatment types. In all antimutagenic acute treatments, BC had a significant antimutagenic/radioprotective activity in relation to 131I. In subchronic antimutagenic treatments, BC reduced the damage that was caused by the radioisotope; however, this reduction was not statistically significant because of the relatively low percentage of chromosomal abnormalities that were observed with only 131I compared to the acute treatment. These results demonstrate the radioprotective and antimutagenic activity of BC, indicating its use by the population, which inevitably is exposed to mutagenic agents, as a means of health protection.

Cytotoxicity of isolated compounds from Picrasma crenata (Vell.) Engl. in animal tumor cell (HTC).

The study aim was to evaluate the cytotoxic activity, using the MTT test [3-(4,5-Dimethilthiazol-2-yl)-2,5-diphenil tetrazolium bromide], from the crude extract of Picrasma crenata (Pau Tenente) and its isolated compounds, quassin and parain, in culture of rat liver tumor cells (HTC). The test was carried out exposing the cells for 24, 48 and 72 hours to concentrations of 5, 10, 50, 100, 200, 300, 400, 500 and 1000 µg of crude extract of Pau Tenente/mL of culture medium and 1, 5, 10, 15, 20, 40, 60, 80 and 100 µg of quassin or parain compounds/mL of culture medium. The absorbances averages results obtained showed that the crude extract did not present cytotoxicity for the HTC cells in all the concentrations and evaluated times. For quassin, the concentrations of 80 and 100 µg/mL were cytotoxic, after 72 hours of treatment. For parain, the concentrations of 1, 5, 20, 40, 60, 80 and 100 µg/mL, in 72 hours, were cytotoxic, revealing a new activity for this compound. Thus, the results demonstrate a first indication of the cytotoxic activity of compounds quassin and parain, adding an important social and economic value to them, and may have application in future research and in pharmaceutical industry.

Cytotoxicity of capsaicin and its analogs in vitro.

Capsaicin (CAP) is the main compound responsible for the spicy flavor of Capsicum plants. However, its application can be inhibited due to its pungency and toxicity. This study aimed to evaluate and compare the cytotoxic effect of CAP and its analogs N-benzylbutanamide (AN1), N-(3-methoxybenzyl) butanamide (AN2), N-(4-hydroxy-3-methoxybenzyl) butanamide (AN3), N-(4-hydroxy-3-methoxybenzyl) hexanamide (AN4) and N-(4-hydroxy-3-methoxybenzyl) tetradecanamide (AN5) on the hepatoma cells of Rattus norvegicus using the MTT test. The results showed cytotoxicity of CAP at concentrations of 100, 150, 175, and 200 µM (24 hours), AN1 at 150 and 175 µM (48 hours), AN2 at 50 µM (24 hours) and 10, 25, 50, and 75 µM (48 hours), AN4 at 175 µM (24 hours), and AN5 at 50 µM (48 hours). Removing the hydroxyl radical from the vanillyl group of capsaicin, together with reducing the acyl chain to 3 carbons, which is the case of AN2, resulted in the best biological activity. Increasing the carbon chain in the acyl group of the capsaicin molecule, which is the case of AN5, also showed evident cytotoxic effects. The present study proves that the chemical modifications of capsaicin changed its biological activity.

Cytotoxic/antiproliferative and nutraceutical activity of aqueous and ethanolic extracts of green and mature Averrhoa carambola.

Averrhoa carambola L. presents in its composition diversity of nutrients and vitamins. The present study aimed to extract water and fat-soluble compounds from this fruit at different stages of maturation (green and mature), perform the physical-chemical characterization as well as evaluate its cytotoxicity against hepatoma cells of Rattus norvegicus (HTC). The physicochemical results showed that the pH and molar acidity is influenced by the fruit maturation state. The fruit presented high percentage of moisture, while the percentage of total minerals (ash) increased according to its maturation stage. The results of the phytochemical screening showed that star fruits present phenolic compounds. The antioxidant activity showed greater potential for the ethanolic extracts of the green and mature star fruit. For HTC cells treated with ethanolic extract of green and mature star fruit the data show absence of cytotoxic effect. The tests with the aqueous extract showed cytotoxic/antiproliferative effect of green and mature star fruit extract, in 24, 48 and 72 hours. The presence of nutraceutical compounds and the cytotoxic/antiproliferative activity were more expressive in the aqueous extract, being an option of easily accessible solvent economic and not harmful to organisms.

Social and behavioral determinants as risk of sexually transmitted diseases. Report by a sample from the Sexually Transmitted Disease Unit in Florence, Italy.

AIM: Sexually transmitted infections (STIs) are increasing worldwide, mostly due to changing sexual behavior s (larger numbers of sexual partners, concurrent relationships, increasing proportion of adolescents engaging in sexual intercourse at young age, and inconsistent condom use with new partners). In Italy, few data are available about STI spread, since most infections are not subjected to mandatory notification. METHODS: In this article, the occurrence of STIs in a random sample attending a STI Unit in Florence, Italy, is reported. Results were obtained through the administration of an anonymous questionnaire that patients could complete spontaneously in the waiting room while waiting for the visit. Self-reported questions allowed to collect information about socio-demographic and clinical data, sexual behavior and perception of risk. RESULTS: Overall, 469 patients (321 males, 148 females) participated in the study. Age ranged from 16 to 70 years. Male patients who referred to engage sexual intercourse with men (MSM) were 133; females who had sex with women (FSF) were 5, while 24 patients declared to have sex with both males and females (bisexual); 59.7% (N.=280) of participants reported they had a stable relationship, but 20% of these reported they had had sex with more than five partners during the last 12 months. The use of condoms is declared to be very infrequent, especially in the two extreme age ranges. Fifty percent of patients had been diagnosed an STI in their life, particularly syphilis (39.3%), genital warts (64.6%) and chlamydial infections (42.9%). Among those subjects who had contracted an STI (including non-curable viral infections, i.e., HIV and herpes genitalis) 32.4% referred they never used condoms. CONCLUSION: The authors discuss their results compared to the existing literature, and focus on identification of risk factors associated with self-reported STIs. Although conducted on a small population, this study provides a basis for targeting prevention and control strategies on our high-risk patients.

The direct economic cost of pharmacologically-treated diabetes in Italy-2006. The ARNO observatory.

AIMS/HYPOTHESIS: To estimate the prevalence and the direct cost of pharmacologically-treated diabetes in Italy. METHODS: The ARNO observatory database, containing the 20-year medical prescriptions of over 10 million Italian people, was used. Ten-year longitudinal data were available in 22 Local Health Districts (LHD). Subjects were classified as having diabetes when prescribed glucose-lowering drugs (oral agents or insulin) (311,979 individuals in 2006). The direct cost was calculated as the sum of drug use, financial compensation by LHD for the inpatient (hospital DRG) and outpatient activities (consultations, laboratory tests, radiology, etc.), all regulated by government contracts. Individuals with diabetes were compared with pharmacologically-treated subjects without diabetes, pair-matched for age, sex and general practitioner. RESULTS: In the 10-year period, the prevalence of pharmacologically-treated diabetes increased from 3.08% to 4.45% (P for trend, <0.001). The average pro capita cost totaled €2,589 in 2006 (95% confidence interval (CI), 2,584-2,594), corresponding to a rate ratio vs. no-diabetes of 1.54 (95% CI, 1.50-1.56). The cost of drugs was € 827 (rate ratio, 1.80 vs. no-diabetes; 95% CI, 1.79-1.82), that of service use, € 488 (rate ratio, 1.07 (0.93-1.25). Only 20% of the pharmaceutical cost was due to glucose-lowering drugs, a percentage stable through the years. The cost of any hospital admission, as defined by DRGs, was independent of diabetes, but the overall cost was much higher in diabetes due to much higher admission rates. Cardiovascular complications and renal failure accounted for the large majority of excess hospital cost. CONCLUSION: The direct economic burden of pharmacologically-treated diabetes on the National Health System is very high, due to the growing prevalence of disease and the cost of complications.

A Ge.F.I. - ISFG European collaborative study on DNA identification of Cannabis sativa samples using a 13-locus multiplex STR method.

Cannabis sativa is the most used controlled substance in Europe. With the advent of new and less restrictive European laws on cannabis sale for recreational use (including in Italy), an increase in indoor cannabis crops were observed. This increase was possible due to the availability of cannabis seeds through the internet market. Genetic identification of cannabis can link seizures and if in possession then might aid in an investigation. A 13-locus multiplex STR method was previously developed and validated by Houston et al. A collaborative exercise was organized by the Italian Forensic Geneticists - International Society of Forensic Genetics (Ge.F.I. - ISFG) Working Group with the aim to test the reproducibility, reliability and robustness of this multiplex cannabis STR kit. Twenty-one laboratories from three European countries participated in the collaborative exercise and were asked to perform STR typing of two cannabis samples. Cannabis DNA samples and the multiplex STR kit were provided by the University of Barcelona and Sam Houston State University. Different platforms for PCR amplification, capillary electrophoresis (CE) and genotyping software were selected at the discretion of the participating laboratories. Although the participating laboratories used different PCR equipment, CE platforms and genotyping software, concordant results were obtained from the majority of the samples. The overall genotyping success ratio was 96%. Only minor artifacts were observed. The mean peak height ratio was estimated to be 76.3% and 78.1% for sample 1 and sample 2, respectively. The lowest amount of -1 / + 1 stutter percentage produced, when the height of the parent allele was higher than 8000 RFU, resulted to be less than 10% of the parent allele height. Few common issues were observed such as a minor peak imbalance in some heterozygous loci, some artifact peaks and few instances of allelic drop-out. The results of this collaborative exercise demonstrated the robustness and applicability of the 13-locus system for cannabis DNA profiling for forensic purposes.