The management of endoscopic retrograde cholangio- pancreatography-related infections risk: results of an italian survey at regional level.

Background and aim: Among the Endoscopic retrograde cholangiopancreatography (ERCP) adverse events, an increasingly arising problem is the transmission of Multi Drug Resistant (MDR) Bacteria through duodenoscopes. The aim of this survey was to evaluate the current clinical practice of management of ERCP associated infections in Emilia-Romagna, Italy. Methods: An online survey was developed including 12 questions on management of ERCP associated infections risk. The survey was proposed to all 12 endoscopy centers in Emilia Romagna that perform at least > 200 ERCPs per year. Results: 11 centers completed the survey (92%). Among all risk factors of ERCP infections, hospitalization in intensive care units, immunosuppressant therapies, and previous MDR infections have achieved a 80 % minimum of concurrence by our respondents. The majority of them did not have a formalized document in their hospital describing categories and risk factors helpful in the detection of patients undergoing ERCP with an high-level infective risk (9/11, 82%). Most centers (8/11, 72%) do not perform screening in patients at risk of ERCP infections. Post procedural monitoring is performed by 6 of 11 centers (55%). Conclusion: Our survey showed that, at least at regional level, there is a lack of procedures and protocols related to the management of patients at risk of ERCP infections.

Do we trust scientific evidence? A multicentre retrospective analysis of first IVF/ICSI cycles before and after the OPTIMIST trial.

STUDY QUESTION: Has the practice of individualizing the recombinant-FSH starting dose been superseded after the largest randomized controlled trial (RCT) in assisted reproduction technology (ART), the OPTIMIST trial? SUMMARY ANSWER: The OPTIMIST trial has influenced our ART daily practice to a limited degree, but adherence is still generally poor. WHAT IS KNOWN ALREADY: Although the 'one size fits all' approach has been discouraged for decades by most authors, the OPTIMIST study group demonstrated in a large prospective RCT that, in general, dosage individualization does not improve the prospects for live birth, although it may decrease ovarian hyperstimulation syndrome (OHSS) risk in expected high responders. STUDY DESIGN, SIZE, DURATION: Retrospective analysis of all first in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles from 1st January 2017 to 31st December 2018, before and after the OPTIMIST publication on November 2017. PARTICIPANTS/MATERIALS, SETTING, METHODS: Two thousand six hundred and seventy-seven patients, between 18 and 42 years old, undergoing their first IVF-ICSI cycle in seven Italian fertility centres, were included. Patients were allocated to three groups according to their ovarian reserve markers: predicted poor ovarian responders (POR), predicted normo-responders (NR) and expected hyper-responders (HRs). MAIN RESULTS AND THE ROLE OF CHANCE: Between 2017 and 2018, there was an overall increase in prescription of the standard 150 IU dose proposed by the OPTIMIST trial and a reduction in the use of a starting dose >300 IU. After subgroup analysis, the decrease in doses >300 IU remained significant in the POR and NR sub-groups. LIMITATIONS, REASONS FOR CAUTION: The retrospective nature of the study. Physicians need time to adapt to new scientific evidence and a comparison between 2017 and 2019 may have found a greater impact of the Optimist trial, although other changes over the longer time span might have increased confounding. We cannot be sure that the observed changes can be attributed to knowledge of the OPTIMIST trial. WIDER IMPLICATIONS OF THE FINDINGS: Clinicians may be slow to adopt recommendations based on RCTs; more attention should be given to how these are disseminated and promoted. STUDY FUNDING/COMPETING INTEREST(S): No external funding was used for this study. E.P. reports grants and personal fees from MSD, grants from Ferring, from IBSA, grants and personal fees from Merck, grants from TEVA, grants from Gedeon Richter, outside the submitted work. E.S. reports grants from Ferring, grants and personal fees from Merck-Serono, grants and personal fees from Theramex, outside the submitted work. All other authors do not have conflicts of interest to declare. TRIAL REGISTRATION NUMBER: Not applicable.

Optimal processing of ESD specimens to avoid pathological artifacts.

BACKGROUND: En bloc endoscopic submucosal dissection (ESD) has been recently introduced as a treatment for precancerous/neoplastic gastrointestinal conditions. The aim of the present study was histological assessment of en bloc ESD specimens. METHODS: Fifty-three ESD specimens were positioned over a cellulose acetate support (40 specimens; 12 from the upper gastrointestinal tract and 28 from the lower gastrointestinal tract) or pinned with nails on polystyrene or cork (13 specimens; 7 from the upper gastrointestinal tract and 6 from the lower gastrointestinal tract). We cut consecutive 2 mm-thick sections stained with hematoxylin and eosin. From the first and the last sections, we obtained a second slide, after a 180° rotation and re-embedding. The quality of ESD samples was scored as inadequate, suboptimal and adequate, based on the amount of crushing, shearing and stretching artifacts that were scored from 0 (absent) to 2 (diffuse or maximum). From the sum of these we obtained a global artifact score (GAS). RESULTS: Removed lesions were: adenocarcinoma (5 cases), neuroendocrine tumor (NET) G1 (1 case), premalignant conditions, including adenomatous polyps (41 cases) and hyperplastic lesions (6 cases). A positive deep surgical margin was found in 8/53 cases (15%): high- and low-grade dysplastic glands were detected in 5 cases, low-grade adenocarcinoma in 2, and NET cells in 1. Dysplastic glands were detected in the lateral surgical margins of 12 ESD specimens (23%). Among the ESD specimens positioned on the cellulose acetate support, apart from the modifications due to electrocoagulation, 2 (5%) showed shearing modifications. In the group of ESD specimens fixed with nails, 5 (38%) showed shearing, 10 (77%) crushing artifacts, 11 (85%) stretching and 11 (85%) multiple holes caused by the nails. On the basis of these data all histological specimens from ESD on cellulose acetate were adequate (GAS 0-1).However, in the group of ESD fixed with nails, 1 was adequate (GAS 0), 11 suboptimal (GAS 2-5) and 1 inadequate (GAS 6). CONCLUSIONS: Specific devices including cellulose support and adequate sampling blocks can be helpful to perform accurate histological assessment of ESD specimens after en bloc ESD for precancerous/neoplastic gastrointestinal lesions, with complete analysis of the status of the margins and the entirely en bloc evaluation of the lesion.

Barriers against split-dose bowel preparation for colonoscopy.

OBJECTIVE: Although split regimen is associated with higher adenoma detection and is recommended for elective colonoscopy, its adoption remains suboptimal. The identification of patient-related barriers may improve its implementation. Our aim was to assess patients' attitude towards split regimen and patient-related factors associated with its uptake. DESIGN: In a multicentre, prospective study, outpatients undergoing colonoscopy from 8:00 to 14:00 were given written instructions for 4 L polyethylene glycol bowel preparation, offering the choice between split-dose and day-before regimens and emphasising the superiority of split regimen on colonoscopy outcomes. Uptake of split regimen and association with patient-related factors were explored by a 20-item questionnaire. RESULTS: Of the 1447 patients (mean age 59.2±13.5 years, men 54.3%), 61.7% and 38.3% chose a split-dose and day-before regimens, respectively. A linear correlation was observed between time of colonoscopy appointments and split-dose uptake, from 27.3% in 8:00 patients to 96% in 14:00 patients (p<0.001, χ2 for linear trend). At multivariate analysis, colonoscopy appointment before 10:00 (OR 0.14, 95% CI 0.11 to 0.18), travel time to endoscopy service >1 h (OR 0.55, 95% CI 0.38 to 0.79), low education level (OR 0.72, 95% CI 0.54 to 0.96) and female gender (OR 0.74, 95% CI 0.58 to 0.95) were inversely correlated with the uptake of split-dose. Overall, the risk of travel interruption and faecal incontinence was slightly increased in split regimen patients (3.0% vs 1.4% and 1.5% vs 0.9%, respectively; p=NS). Split regimen was an independent predictor of adequate colon cleansing (OR 3.34, 95% CI 2.40 to 4.63) and polyp detection (OR 1.46, 95% CI 1.11 to 1.92). CONCLUSION: Patient attitude towards split regimen is suboptimal, especially for early morning examinations. Interventions to improve patient compliance (ie, policies to reorganise colonoscopy timetable, educational initiatives for patient and healthcare providers) should be considered. TRIAL REGISTRATION NUMBER: NCT02287051; pre-result.

Radiofrequency ablation for chronic radiation proctitis: our initial experience with four cases.

BACKGROUND: Chronic radiation proctitis (CRP) occurs up to 20 % of patients after pelvic radiotherapy, with rectal bleeding as the main presenting complaint. Radiofrequency ablation (RFA) has recently been used in the management of Barrett's esophagus, but its efficacy in CRP has to be studied. The aim of this case series was to describe four cases of patients with CRP treated with RFA that demonstrate the efficacy and safety of the technique. METHODS: All the procedures were performed with HALO 90 or HALO 90 Ultra ablation catheter fitted on the distal end of a standard flexible endoscope. For each patient, the severity of symptoms was assessed at baseline and after the last treatment session. RESULTS: At least two sessions of RFA (maximum 4) were necessary, at three-month intervals, to completely control the symptoms. No major complications were observed. CONCLUSIONS: RFA was effective and safe for control bleeding in this case series. Adequately powered randomized controlled trials are needed to establish the safety and efficacy of RFA for CRP.

[Chemical risk assessment in the construction industry: principles and critical issues]. / Valutazione del rischio chimico in edilizia: principi e criticità.

Risk assessment (RA) represents the first step to ensure the protection of the workers' health in all work sectors, production and services included. For this reason RA has become a legal duty for the occupational physician in his/her professional activity. The basic concepts of RA have been developed as a formal procedure for the management of chemical risks but they are currently applied to protect human health against all types of occupational and environmental risk factors. In the construction industry, in particular, chemical risk assessment is specially difficult due to the complexity of the working condition, and the variability and multiplicity of exposure. The critical aspects of RA in the construction industry will be discussed here, in the attempt to highlight how the occupational physician, making use of traditional and new tools, including biological monitoring, can address and partly overcome them.

Endoscopic treatment of gastrointestinal fistulas using an over-the-scope clip (OTSC) device: case series from a tertiary referral center.

Gastrointestinal perforations and post-surgical fistulas are dreaded complications that dramatically increase morbidity and mortality. A new endoscopic over-the-scope clip (OTSC) system may be potentially useful for sealing visceral perforations in several clinical settings. We evaluated the advantages and clinical impact of the placement of OTSCs on the management of non-malignant gut leaks in 12 consecutive patients. OTSCs of 9.5 or 10.5 mm were used, according to the diameter of the defect within the wall. The indications for treatment were mainly related to post-surgical fistulas. Healing of the fistula was assessed by endoscopic or radiological means, and failed only once. No OTSC-related complications occurred. Endoscopic closure of perforations and post-surgical fistulas with the OTSC system is a simple and minimally invasive technique. This approach, when feasible, may be less expensive and more advantageous than a surgical approach.

Anti-Müllerian hormone-based prediction model for a live birth in assisted reproduction.

Prediction of assisted reproduction treatment outcome has been the focus of clinical research for many years, with a variety of prognostic models describing the probability of an ongoing pregnancy or a live birth. This study assessed whether serum anti-Müllerian hormone (AMH) concentrations may be incorporated into a model to enhance the prediction of a live birth in women undergoing their first IVF cycle, by analysing a database containing clinical and laboratory information on IVF cycles carried out between 2005 and 2008 at the Mother-Infant Department of University Hospital, Modena. Logistic regression was used to examine the association of live birth with baseline patient characteristics. Only AMH and age were demonstrated in regression analysis to predict live birth, so a model solely based on these two criteria was generated. The model permitted the identification of live birth with a sensitivity of 79.2% and a specificity of only 44.2%. In the prediction of a live birth following IVF, a distinction, however moderate, can be made between couples with a good and a poor prognosis. The success of IVF was found to mainly depend on maternal age and serum AMH concentrations, one of the most relevant and valuable markers of ovarian reserve.

Symptoms after mould exposure including Stachybotrys chartarum, and comparison with darkroom disease.

BACKGROUND: Mould-attributed symptoms have included features which overlap with unexplained syndromes such as sick building syndrome. OBJECTIVES: We describe questionnaire and chart review findings in patients following exposure to moulds which include Stachybotrys and compare responses with two control groups. METHODS: Thirty-two patients presented with symptoms attributed to mould exposures. Exposure identification for 25 patients had reported S tachybotrys chartarum as well as other mould (Aspergillus, Penicillium), 88% at work. The remaining seven had professionally visualized or self-reported/photographic exposure evidence only. A chart review was performed and a follow-up with a questionnaire, including questions on current health status, and nonspecific symptoms. RESULTS: Cough, shortness of breath and chest tightness (at presentation) were reported in 79%, 70% and 64%, respectively, and persisted >6 weeks in 91%. Skin test(s) were positive to fungal extract(s) in 30%. Seventeen returned questionnaires were obtained 3.1 (SD 0.5) years after the initial clinic assessment. Among this subgroup, persisting asthma-like symptoms and symptoms suggestive of sick building syndrome were frequent, and similar to a group previously assessed for darkroom disease among medical radiation technologists. The mould-exposed group more commonly reported they were bothered when walking in a room with carpets, complained of a chemical or metallic taste in their mouth, and had problems in concentration when compared with a control physiotherapist group (P < 0.005). CONCLUSIONS: Although only a minority with health concerns from indoor mould exposure had demonstrable mould-allergy, a significant proportion had asthma-like symptoms. Other symptoms were also common and persistent after the initial implicated exposure.

[Quality in occupational health education and training]. / La qualità della formazione in medicina del lavoro.

According to the International Code of Ethics of the International Commission on Occupational Health (ICOH) "occupational health practice must be performed according to the highest professional standards and ethical principles". So, the first ethical requirement for an occupational physician is a scientifically and professionally sound conduct, and vice-versa, the ethical principles must be an integral part of his/her education and training. The different tools and contexts for the education and training in occupational health (OH) in Italy, at both the undergraduate and postgraduate level, are presented. Moreover, the past and present contribution of the academic institutions and professional associations active in occupational health, to improve the professional standards of the occupational physicians is discussed. It is suggested that the objectives and the contents in OH education and training should not be limited to simply fulfil the legal requirements aimed to the protection of health and safety in the workplace (as it seems to be largely the case today), but they should rather anticipate and overcome them, by also including a thorough discussion of the fundamental ethical principles and duties to be accomplished in OH.

[Comparison of the training schemes of the specialization schools of the public health area: a rational basis for a proposal of a core curriculum for the university training programme contained in article 38 of Legislative Decree (D.Lgs) 81/2008]. / Confronto dei contenuti formativi delle scuole di specializzazione dell'Area di Sanità Pubblica: le basi razionali per una proposta di core curriculum per il percorso formativo universitario ex art. 38, D.Lgs 81/2008.

A document by the B. Ramazzini College of University Teachers of Occupational Medicine of the Italian Society of Occupational Health and Industrial Hygiene (S.I.M.L.I.I). The aim of this document was to compare the professional competence, training profile and core curricula of the three main specialization courses in the Public Health postgraduate medical area, i.e., Occupational Medicine, Hygiene and Preventive Medicine, and Forensic Medicine, such as contained in the Ministerial Decree (D.M) of 1 August 2005. We set out to identify, using clear and objective criteria, the knowledge and skills that specialists in Hygiene or Forensic Medicine must develop, in accordance with Art. 38 of the new Italian law on safety ahd health at work (D.Lgs 81/2008), in order to be authorized to perform occupational health activities as "Competent Physicians" (CP). The comparison revealed significant differences in structure and content among the three courses. In particular, compared to the course in Occupational Medicine, the courses in Hygiene and in Forensic Medicine both lack clinical training, including diagnostic and therapeutic skills, risk-oriented occupational health activities, biological monitoring, assessment of individual susceptibility, and clinical or instrumental procedures to prevent and detect occupational diseases. Furthermore, the specialization course in Hygiene lacks any training regarding the criteria and methods for assessing the individual worker's fitness for work, while the course in Forensic Medicine lacks any training in occupational risk assessment and management. From this comparison, a list was derived of the education and training debits that specialists in Hygiene or Forensic Medicine should cover (credits) in order to be authorized to perform CP activities as indicated by the new law. A core curriculum is proposed here, based on the corresponding credits, for use as a reference.

Association of apolipoprotein E polymorphisms and dietary factors in colorectal cancer.

ApoE single nucleotide polymorphisms (SNPs) Cys112Arg (Epsilon-4), and Arg158Cys (Epsilon-2) have been implicated in cardiovascular and Alzheimer's disease, but their role in colorectal cancer (CRC) has not been extensively studied. We investigated whether ApoE polymorphisms alone or in combination with dietary factors selectively contribute to mismatch-repair (MMR) proficient (microsatellite stable/low or MSS/L) vs deficient (microsatellite unstable or MSI-H) CRCs. We carried out a case-control study with 906 CRC cases and 911 unaffected controls to examine the associations between ApoE polymorphisms and dietary factors and assessed their contribution to MSS/L and MSI-H CRCs. We used unconditional logistic regression to evaluate the associations between ApoE SNPs, tumour MSI status, and dietary factors after adjusting for age and sex. All statistical tests were two-sided. No significant differences in ApoE genotype frequencies were observed between CRC cases and unaffected controls. We observed that increased dietary intake of total fat, saturated fat, cholesterol, and red meat was significantly associated with CRC. Among non-ApoE4 carriers, 2-4 and >4 red meat servings/week were associated with developing MSS/L CRC (OR=1.51, 95% CI 1.10-2.07 and OR=1.80, 95% CI 1.30-2.48, respectively), whereas among ApoE4 allele carriers, four or more red meat servings/week were associated with MSI-H CRC (OR=4.62, 95% CI 1.20-17.77) when compared with the controls. ApoE isoforms modulate the risk of MSI-H and MSS/L CRCs among high red meat consumers.

Bulk spin polarization of Co(1-x)Fe(x)S2.

We report on a new method to determine the degree of bulk spin polarization in single crystal Co(1-x)Fe(x)S2 by modeling magnetic Compton scattering with ab initio calculations. Spin-dependent Compton profiles were measured for CoS2 and Co0.9Fe0.1S2. The ab initio calculations were then refined by rigidly shifting the bands to provide the best fit between the calculated and experimental directional profiles for each sample. The bulk spin polarizations, P, corresponding to the spin-polarized density of states at the Fermi level, were then extracted from the refined calculations. The values were found to be P=-72+/-6% and P=18+/-7% for CoS2 and Co0.9Fe0.1S2, respectively. Furthermore, determinations of P weighted by the Fermi velocity (v(F) or v(F)2) were obtained, permitting a rigorous comparison with other experimental data and highlighting the experimental dependence of P on v(F).

The minority spin surface bands of CoS(2)(001).

Angle-resolved photoemission was used to study the surface electronic band structure of high quality single crystals of ferromagnetic CoS(2) (below 120 K). Strongly dispersing Co t(2g) bands are identified along the ⟨100⟩ [Formula: see text] direction, the [Formula: see text]-[Formula: see text] line of the surface Brillouin zone, in agreement with model calculations. The calculated surface band structure includes corrections for the previously determined surface structure of CoS(2)(001) and is in general agreement with the experimental photoemission spectra in the region of the Fermi level. There is evidence of the existence of several minority spin surface states, falling into a gap of the projected minority spin bulk CoS(2)(001) band structure.

Colo-rectal endoscopic full-thickness resection (EFTR) with the over-the-scope device (FTRD®): A multicenter Italian experience.

BACKGROUND AND AIM: Endoscopic full-thickness resection(EFTR) with FTRD® in colo-rectum may be useful for several indications.The aim was to assess its efficacy and safety. MATERIAL AND METHODS: In this retrospective multicenter study 114 patients were screened; 110 (61M/49F, mean age 68 ±â€¯11 years, range 20-90) underwent EFTR using FTRD®. Indications were:residual/recurrent adenoma (39), incomplete resection at histology (R1 resection) (26), non-lifting lesion (12), adenoma involving the appendix (2) or diverticulum (2), subepithelial lesions(10), suspected T1 carcinoma (16), diagnostic resection (3). Technical success (TS: lesion reached and resected), R0 resection (negative lateral and deep margins),EFTR rate(all layers documented in the specimen) and safety have been evaluated. RESULTS: TS was achieved in 94.4% of cases. EFTR was achieved in 91% with lateral and deep R0 resection in 90% and 92%. Mean size of specimens was 20 mm (range 6-42). In residual/recurrent adenomas, final analysis revealed: low-risk T1 (11), adenoma with low-grade dysplasia (LGD) (24) and high-grade dysplasia (HGD) (3), scar tissue (1). Histology reports of R1 resections were: adenoma with LGD (6), with HGD (1), low-risk (6) and high-risk (1) T1, scar tissue (12). Non-lifting lesions were diagnosed as: adenoma with HGD (3), low-risk (7) and high risk (2) T1. Adverse clinical events occurred in 12 patients (11%),while adverse technical events in11%. Three-months follow-up was available in 100 cases and residual disease was evident in only seven patients. CONCLUSIONS: EFTR using FTRD® seems to be a feasible, effective and safe technique for treating selected colo-rectal lesions. Comparative prospective studies are needed to confirm these promising results.

The influence of sampling duration on recovery of culturable fungi using the Andersen N6 and RCS bioaerosol samplers.

UNLABELLED: The influence of sampling duration on recovery of culturable fungi was compared using the Andersen N6 and the Reuter Centrifugal Sampler (RCS). Samplers were operated side-by-side, collecting 15 samples each of incrementally increasing duration (1-15 min). From 270 samples collected, 26 fungal genera were recovered. Species of Alternaria, Aspergillus, Cladosporium, Epicoccum, Penicillium and Ulocladium were most frequent. Data adjusted to CFU/m3 were fitted to a Poisson regression model with a logarithmic link function and evaluated for the impact of sampling time on qualitative and quantitative recovery of fungi, both as individual taxa and in aggregate according to xerotolerance. Significant differences between the two samplers were observed for xerotolerant and normotolerant moulds, as well as Aspergillus spp. and Cladosporium spp. With the exception of Cladosporium spp., overall recoveries were higher with the RCS. When the Andersen N6 was used, the recovered levels of Cladosporium spp. and unidentified yeasts were reduced significantly at sampling times over 6 min. Similarly, when the RCS was used, recovery of Aspergillus spp., Penicillium spp., Ulocladium spp., unidentified yeasts, and low water activity fungi declined significantly at sampling times over 6 min. PRACTICAL IMPLICATIONS: Currently, the industry-wide trend for viable air sampling in indoor environmental investigations is to use sampling times between 2 and 4 min in duration. Our results support the routine use of a 6-min sampling time where low spore loads are expected, resulting in improved limits of detection.

Scuba diving death: Always due to drowning? Two forensic cases and a review of the literature.

Scuba diving is an increasingly common recreational activity. We describe the physiopathology of barotrauma in two cases where death was caused by pulmonary barotrauma while diving. An inspection and autopsy were carried out in both cases. The autopsy data were supported by post-mortem radiological investigation. Histological and toxicological analyses were also carried out, and dive computer and tank manometer analysis performed. In both cases, the cause of death was attributable to arterial gas embolism, resulting from pulmonary barotrauma subsequent to pulmonary over-distension. The dive computer analysis and the tank manometer allowed us to understand what happened underwater. In our opinion, a multidisciplinary approach is crucial in order to clarify the cause of death. Some pathological conditions and risk factors should be considered before diving.

Multimodal Surgical Approach for Adult Patients With Chronic Intestinal Pseudo-Obstruction: Clinical and Psychosocial Long-term Outcomes.

BACKGROUND: Clinical and psychosocial outcomes of a multimodal surgical approach for chronic intestinal pseudo-obstruction were analyzed in 24 patients who were followed over a 2- to 12-year period in a single center after surgery or intestinal/multivisceral transplant (CTx). METHODS: The main reasons for surgery were sub-occlusion in surgery and parenteral nutrition-related irreversible complications with chronic intestinal failure in CTx. RESULTS: At the end of follow-up (February 2015), 45.5% of CTx patients were alive: after transplantation, improvement in intestinal function was observed including a tendency toward recovery of oral diet (81.8%) with reduced parenteral nutrition support (36.4%) in the face of significant mortality rates and financial costs (mean, 202.000 euros), frequent hospitalization (mean, 8.8/re-admissions/patient), as well as limited effects on pain or physical wellness. CONCLUSIONS: Through psychological tests, transplant recipients perceived a significant improvement of mental health and emotional state, showing that emotional factors were more affected than were functional/cognitive impairment and social interaction.

Toxicity of recombinant beta-amyloid prefibrillar oligomers on the morphogenesis of the sea urchin Paracentrotus lividus.

A distinctive feature of Alzheimer's disease is the deposition of amyloid beta-protein (Abeta) in senile or diffuse plaques. The 42 residue beta-peptide (Abeta42) is the predominant form found in plaques. In the present work we report a high-yield expression and purification method of production of a recombinant Abeta42. The purified recombinant peptide shows characteristics similar to the synthetic human peptide. Different size aggregates, either small oligomers or larger aggregates, were obtained upon dissolving the recombinant Abeta42 peptide under different conditions at pH 7.2 or pH 3, respectively. We report a new toxicity assay on the morphogenic development of the sea urchin Paracentrotus lividus and study the toxicity of the two kinds of aggregates. Despite the difference between the ionic strength of human extracellular fluid (0.154 mol/l) and artificial sea water (0.48 mol/l), toxicity data collected in this system have an intrinsic relevance. The different ionic strength, in fact, could change the kinetics of oligomer formation, but the effect of morphogenic development reported here is related to the final oligomer sizes. Results of the toxicity assay of Abeta42 on sea urchin development also show a dose-dependent effect. After only 4 h of embryo development, one can note morphological defects in the cell membrane. Retardation of the embryo's development, along with cellular disorders visible inside the blastocoele, can be observed after 1 day of development. Cellular degeneration in two different pathological phenotypes-the occluded blastulae and the occluded prism-is present after 48 h of development. Results show that a greater effect on cell death is induced by the small oligomers stabilized under physiological conditions than at acid pH. In this case only occluded blastulae are found after 48 h of development.