Assessment of the quality of oral biopsy procedure videos shared on YouTube

OBJECTIVE

The aim of this study was to assess the quality of free-to-access videos on oral biopsy procedures on the YouTube platform.

MATERIALS AND METHODS

We conducted a search on YouTube using the term "oral biopsy" and selected the first 100 videos in order of relevance. The following exclusion criteria were applied: language other than English, videos that did not cover oral biopsy techniques, videos on nonhuman specimens, postoperative instructions, personal experiences, exfoliative cytology, or "brush biopsy." Forty-seven selected videos were classified based on their duration, country of origin, date of upload to the system, author, information source and number of views, and likes and dislikes. Video quality was analyzed using DISCERN, the Global Quality Scale (GQS), and the Video Information and Quality Index (VIQI).

RESULTS

The majority (78.7%) of analyzed videos were uploaded by dentists, originating from India (48.9%), with a mean duration of 11.8 min (SD, 20.4), with 104.5 likes (SD, 186.4) and 7.1 dislikes (SD, 10.55). The mean values for DISCERN, GQS, and VIQI were 1.3 (SD, 0.52), 2.1 (SD, 1.04), and 9.62 (SD, 1.69), respectively.

CONCLUSION

The majority of videos on oral biopsy published on YouTube are of low quality.

A Novel Source-Filter Stochastic Model for Voice Production

The novel stochastic model to produce voiced sounds proposed in this paper uses the source-filter Fant theory to generate voice signals and, consequently, it does not consider the coupling between the vocal tract and the vocal folds. Two novelties are proposed in the paper. The first one is the new model obtained from the unification of two other deterministic one mass-spring-damper models obtained from the literature and the second one is to build a stochastic model which can generate and control the level of jitter resulting even in hoarse voice signals or with pathological characteristics but using a simpler model than those ones discussed in the literature. An inverse stochastic problem is then solved for two cases, considering a normal voice and other obtained from a case of paralysis on the vocal folds. The parameters of the model are identified in the two cases allowing the validation of the model.

Expression of spindle assembly checkpoint proteins BubR1 and Mad2 expression as potential biomarkers of malignant transformation of oral leukoplakia: an observational cohort study

Background

The Spindle Assembly Checkpoint (SAC) is a surveillance mechanism essential to ensure the accuracy of chromosome segregation during mitosis. Our aim was to evaluate the expression of SAC proteins in oral carcinogenesis, and to assess their potential in predicting malignant transformation of oral leukoplakia.

Material and Methods

We analysed the immunoexpression of BubR1, Mad2, Bub3, and Spindly proteins in 64 oral biopsies from 52 oral leukoplakias and 12 normal tissues. Univariate and multivariate analysis were performed to evaluate predictive factors for malignant transformation (MT).

Results

We observed that BubR1 and Mad2 were more highly expressed in high dysplasia grade lesions than in low grade or normal tissues (P<0.05). High expression of Spindly was significantly correlated with a high Ki-67 score (P=0.004). Six (11.5%) oral leukoplakias underwent malignant transformation. In univariate analysis, the binary dysplasia grade (high grade) (P<0.001) was associated with a higher risk of malignant transformation as well as high BubR1 (P<0.001) and high Mad2 (P=0.013) expression. In multivariate analysis, high expression of BubR1 and Mad2 when combined showed an increased risk for malignant transformation (P=0.013; HR of 4.6, 95% CI of 1.4-15.1).

Conclusions

Our findings reveal that BubR1 and Mad2 were associated with an increased risk for malignant transformation independently of histological grade and could be potential and useful predictive risk markers of malignant transformation in oral leukoplakias.

Key words:BubR1, Mad2, Spindly, Bub3, Oral Leukoplakia, epithelial dysplasia, Oral squamous cell carcinoma.

An observational retrospective study of odontogenic cyst´s and tumours over an 18-year period in a Portuguese population according to the new WHO Head and Neck Tumour classification

Background

Odontogenic cysts and tumours of the jaws represent one of the most prevalent groups of oral-maxillofacial lesions. We aimed to evaluate the clinical and pathological characteristics of a cohort of odontogenic cysts (OC) and odontogenic tumours (OT) of the jaws in a Portuguese population.

Material and Methods

This observational retrospective study analysed patients diagnosed with either an OC or OT of the jaws at a central hospital of Oporto, Portugal, between 1988 and 2006. Data collected from patients’ files included demographic, clinical, radiological and histopathological information. Recurrence was evaluated using univariate and multivariate analysis.

Results

The sample consisted of 397 patients, 231 males (58.2%) and 166 females (41.8%), with a mean-age of 36.7±17 years. Twenty-seven patients (6.8%) presented with more than one lesion providing a total of 433 lesions. There were 396 (91.5%) OC, mostly represented by radicular cysts (n=257;59.4%), dentigerous cysts (n=79;18.2%), or odontogenic keratocysts (n=50;11.5%). There were 37 (8.5%) OT, mostly represented by ameloblastomas (n=16;3.7%), and odontomas (n=9;2.1%). The most common initial clinical manifestation was swelling (n=224;51.7%). Recurrence was observed in 30 cases (6.9%), mostly in ameloblastomas (n=6;37.5%) and odontogenic keratocysts (n=12;24%). In the multivariate analysis the diagnosis classification of the lesion was the only independent and significant variable related with the recurrence (P=0.04).

Conclusions

Radicular cysts were the most commonly occurring type of OC and ameloblastomas the most commonly occurring OT. Amelobastomas and odontogenic keratocysts were the lesions with the highest rates of recurrence. This large sample provides useful information about the frequency profile and characteristics of OC and OT over a period of 18 years, allowing valuable comparison with data from other countries.

Key words:Odontogenic cysts and tumours, radicular cyst, dentigerous cyst, odontogenic keratocyst, ameloblastoma, recurrence.

Protein Aggregation Patterns Inform about Breast Cancer Response to Antiestrogens and Reveal the RNA Ligase RTCB as Mediator of Acquired Tamoxifen Resistance

Simple Summary

Acquired resistance to antiestrogenic therapy remains the major obstacle to curing luminal subtype breast cancer. While current treatment in acquired endocrine-resistant settings includes combined therapy with receptor tyrosine kinase or cyclin-dependent kinase inhibitors, progression to incurable disease remains possible. In recent years, the antioxidant system and the protein quality control network have been associated with the enhanced resistance of breast cancer cells to hormonal therapy. In this work, we raise the hypothesis that antiestrogen treatment induces the accumulation of protein aggregates in sensitive cells, which in turn could hinder the activation of survival pathways. We present evidence concerning a novel way to identify antiestrogen response and disclose a novel protein, RTBC, that controls acquired antiestrogen resistance. This work opens a new avenue for research towards finding breast cancer prognostic markers and therapeutic targets, where the identification of proteins prone to aggregate could help to identify antiestrogen response and understand mechanisms of disease.

Abstract

The protein quality control network, including autophagy, the proteasome and the unfolded protein response (UPR), is triggered by stress and is overactive in acquired antiestrogen therapy resistance. We show for the first time that the aggresome load correlates with apoptosis and is increased in antiestrogen-sensitive cells compared to endocrine-resistant variants. LC-MS/MS analysis of the aggregated proteins obtained after 4OH-tamoxifen and Fulvestrant treatment identified proteins with essential function in protein quality control in antiestrogen-sensitive cells, but not in resistant variants. These include the UPR modulators RTCB and PDIA6, as well as many proteasome proteins such as PSMC2 and PSMD11. RTCB is a tRNA and XBP1 ligase and its aggregation induced by antiestrogens correlated with impaired XBP1s expression in sensitive cells. Knock down of RTCB was sufficient to restore sensitivity to tamoxifen in endocrine-resistant cells and increased the formation of aggresomes, leading to apoptotic cell death. Analysis of primary human breast cancer samples and their metastases appearing after endocrine treatment showed that RTCB is only localized to aggresomes in the primary tumors, while total aggresomes, including aggregated RTCB, were significantly reduced in the metastases. Therefore, different protein aggregation patterns may indicate loss of function of essential proteins resulting in enhanced protein aggregation that can be used to identify antiestrogen-resistant breast cancer cells and improve the response to antiestrogenic therapy.

UEPG Abraça Program: The importance of a psychosocial care service in the university context

Introduction

In 2018, it was implanted in a Brazilian public university, the UEPG Abraça Extension Program, which has as objectives to realize psychosocial care and accompaniment, offer psychotherapies and therapeutic groups to the university community, that is, students, professors and university staff to suicide prevention, coping with mental disorders and the problematic use of alcohol and other drugs. The Program has a multi-professional team composed of nurses, social worker, psychologists and psychiatrists, in an exclusive environment, thus guaranteeing comfort and secrecy to users.

Objectives

To characterize the socio-demographic and clinical profile of users assisted by the UEPG Abraça Program and to disclose the importance of the service for the promotion of Mental Health.

Methods

Qualitative, quantitative, descriptive study, with a structured questionnaire as the research instrument. The collection took place in 2019 and the target audience were users who sought psychological care.

Results

There were 469 admissions/visits and 35 of them continued with individual visits in 2020. The majority of users were female (58%) and had the age group between 17 and 20 years. The main mental health problems identified were anxiety, self-knowledge and university-related problems such as interpersonal conflicts and difficulties in the work process. The most attended undergraduate courses were Letters, Journalism and Dentistry.

Conclusions

It is noted the importance of a psychosocial care service at university level for the care and promotion of Mental Health.

Disclosure

No significant relationships.

Data integration for infrastructure asset management in small to medium-sized water utilities

Water utilities collect, store and manage vast data sets using many information systems (IS). For infrastructure asset management (IAM) planning those data need to be processed and transformed into information. However, information management efficiency often falls short of desired results. This happens particularly in municipalities where management is structured according to local government models. Along with the existing IS at the utilities' disposal, engineers and managers take their decisions based on information that is often incomplete, inaccurate or out-of-date. One of the main challenges faced by asset managers is integrating the several, often conflicting, sources of information available on the infrastructure, its condition and performance, and the various predictive analyses that can assist in prioritizing projects or interventions. This paper presents an overview of the IS used by Portuguese water utilities and discusses how data from different IS can be integrated in order to support IAM.

Hearing Screening in Preschool Children of a Rural Community in Portugal - A 10-year Experience

Introduction Preschool hearing screening programmes would identify later onset or progressive hearing losses and conductive hearing loss, due to the high prevalence of otitis media with effusion in childhood. Hearing loss associated with otitis media with effusion can have a great impact on reading, writing, central auditory processing and balance.

Objectives The present study aims at characterising the audiological alterations found in preschool children screened in a rural community in Portugal, and the correlation between audiological findings and otoscopy.

Methodology This is an observational study using the results obtained in a ten year audiological and otological screening of preschool children. Otoscopy, Tympanometry and Audiometry (1, 2 and 4 KHz presented at 40 and 20 dB intensity) were performed at the first stage of the screening and the results were classified as “pass” or “refer”. Every non-normal result of any category would imply a second stage consisting of observation by an ENT specialist at the site and the establishing of a follow-up plan. Written Informed Consent was obtained from the parents prior to initiating the study.

Results 595 children aged 5 and 6 years were screened between 2007 and 2017, of whom 192 (32.3%) required referral to the second stage. The most frequent alteration was found in the tympanogram. The tympanograms showed a significant correlation with the otoscopy performed by the ENT doctor, mainly type B tympanograms. The pass/refer audiometry also showed a statistically significant correlation with the medical otoscopy, although weak in all frequencies studied.

Conclusion It’s extremely important to perform a hearing screening in the age range of 5-6 years (with a high predisposition to middle ear problems), with the main objective of identifying and referring for treatment children who present alterations in order to reduce the consequences of the hearing impairment.

Antipsychotics in first-episode psychosis: Patterns of prescription in an inpatient unit

Introduction

The treatment of first-episode psychosis patients is different from those with multiple-episode schizophrenia: the response to antipsychotics is better, the required doses are lower and the sensitivity to side-effects is higher. As such, current guidelines recommend a “start slow, go slow” strategy and an active avoidance of side-effects.

Objectives/aims

To know the patterns of antipsychotic prescription in first-episode psychosis patients of our inpatient unit.

Methods

We retrospectively reviewed the clinical data of all non-affective first-episode psychosis patients admitted to the Inpatient Unit C of Hospital de Magalhães Lemos during 2015. The antipsychotics prescribed at admission and discharge were recorded, as well as the doses.

Results

A total of 29 patients were identified. The mean age was 36.6 and 65.5% were man. At admission, all patients were medicated with second-generation antipsychotics: 62.1% with risperidone, 27.6% with olanzapine, 6.9% with paliperidone and 3.4% with aripiprazol. The mean dose of risperidone was 3.5 mg/day. By the time of discharge, 34.5% of patients were prescribed a depot antipsychotic, half of them risperidone. Among those with oral medication only, 55.5% were prescribed risperidone, 22.2% paliperidone and the remainder 22.3% other antipsychotics (aripiprazol, olanzapine or quetiapine). The mean dose of risperidone was 3.7 mg/day.

Conclusions

Second-generation antipsychotics are clearly preferred. The mean dose by the time of discharge is similar to that used in clinical trials. However, antipsychotics are initiated at doses above the minimum effective dose. On discharge, an important proportion of patients are prescribed depot antipsychotics, which are known to improve medication adherence.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

A histological evaluation of the surgical margins from human oral fibrous-epithelial lesions excised with CO2 laser, Diode laser, Er:YAG laser, Nd:YAG laser, electrosurgical scalpel and cold scalpel

Background

We aim to evaluate the presence of histological artefacts in the surgical margins of human oral fibro-epithelial hyperplasias excised with lasers of different wavelengths, and also electrosurgical scalpel and cold scalpel. Moreover, we aim to determine if some of these instruments could impair the normal histological diagnosis of these lesions.

Material and Methods

We included 130 consecutive surgical samples of 80 females and 50 males (mean age of 53.82±16.55) with a histological diagnosis of an oral benign fibrous-epithelial hyperplasias. The samples were categorized into 6 groups according to the type of instrument used: CO2 laser group, diode laser group, Er:YAG laser group, Nd:YAG laser group, electrosurgical scalpel group and cold scalpel group. Histological instrument-induced changes were microscopic evaluated and related with clinical and pathological variables.

Results

The instrument with highest tissue damage extension (TDE) was the electrosurgical scalpel (1002.2µm±434.92), followed by diode laser (913.73 µm±322.45), Nd:YAG (899.83µm±327.75), CO2 laser (538.37µm±170.50), Er:YAG laser (166.47µm±123.85), and at last with fewer alterations the cold scalpel group (2.36µm±7.27) (P< 0.001). The most regular incision was observed in CO2 laser group, followed by Er:YAG laser, Nd:YAG laser, electrosurgical scalpel and diode laser group with the less regular incision using cold scalpel as comparison (P< 0.001). A correlation was found between the incision score and TDE (P< 0.001). Regarding histological diagnosis, no case showed any limitation of diagnosis related with the use of any instrument evaluated.

Conclusions

Our results suggest that lasers can be used for the excision of oral benign fibrous-epithelial hyperplasias, without hispathological diagnosis limitations, as long as the physical properties of each laser are known and respected. Er:YAG laser have shown to be a laser with few tissue damage extension and with good incision regularity, been a possible instrument of choice for the surgical removal of these lesions.

Key words:CO2 laser, diode laser, Er:YAG laser, Nd:YAG laser, oral mucosa.

Prevalence of calcifications in soft tissues visible on a dental pantomogram: A retrospective analysis

OBJECTIVES

To determine the frequency and spectrum of soft tissues calcifications identified on Dental Pantomograms (DPT) at a University Dental Clinic in the northern region of Portugal and to compare the data obtained with those published in the literature.

METHODS

We conducted a 3-year descriptive analysis (2012-2014) of DPT calcifications within soft tissues at the University Clinic (CESPU), in Oporto, Portugal. Information on gender, age, location of the lesions and the radiographic diagnosis were analysed. DPTs were interpreted by two examiners (Kappa test 0.8). Data were entered into a database and analysed with Chi-square and Fisher exact tests. Statistical analysis was performed using the Kolmogorov-Smirnov and Shapiro-Wilk test.

RESULTS

2375 DPTs were analysed, with 468 calcifications observed in the radiographs of 420 individuals. Calcifications of the stylohyoid and stylomandibular ligament were most common, with atheroma, sialoliths, tonsilloliths rhinoliths and antroliths also identified. A statistically significant relationship was observed between the presence of calcifications of the stylohyoid and stylomandibular ligaments, atheromatous calcifications in the carotid artery and tonsilloliths in individuals older than 40.

CONCLUSIONS

This is the largest sample analysis ever done in Portugal, providing useful information about the incidence and distribution of soft tissue calcifications identifiable on DPTs, allowing valuable comparison with other countries.

ADVANCES IN KNOWLEDGE

Despite mostly being incidental findings, panoramic radiography can be the first relevant test that aids dental practitioners in the process of requesting other imaging techniques or forwarding to the correct specialty.

Coffee is protective against oral and pharyngeal cancer: A systematic review and meta-analysis

OBJECTIVES

Coffee is one of the most popular and consumable drinks worldwide. However, there are conflicting results on the influence of this drink in oral and pharyngeal cancer risk. To clarify this, we aimed to systemically review and carry out a meta-analysis of the relevant literature on the association between coffee and oral and pharyngeal cancer.

STUDY DESIGN

We carried out an electronic search of publications up to August 2016 from PubMed, National Library of Medicines Medline, Embase, Science Direct and the Cochrane Central Register. The Newcastle-Ottawa scale was used to address the quality of the studies a meta-analysis was carried out using random-effects models.

RESULTS

From the 22,515 entries identified in the search, 13 case-control and 4 cohort studies were selected. With regards to quality on the Newcastle-Ottawa scale, an overall value of 6.06 was obtained. The analysis for oral and pharyngeal cancer grouped together indicated a pooled OR of .69 (95% CI of .57-.84; p<.001) for high versus low coffee consumption with a moderate heterogeneity (I2: 50.3%; p=.009). Regarding studies on oral cavity cancers we observed a pooled OR of 0.82; 95% CI =.58-1.16; p=.257) and for pharyngeal cancers a pooled OR of .72 (95% CI of 0.54-.95; p=.019). There was no significant publication bias.

CONCLUSION

The results show an inverse association between high coffee consumption and the risk of oral and pharyngeal cancers, which indicates that coffee may have a protective role against these cancers. Further larger prospective observational cohort studies are needed to address any effect of other possible co-factors.

Type of surgical treatment and recurrence of oral leukoplakia: A retrospective clinical study

BACKGROUND

Oral leukoplakia (OL) is the most typical potentially malignant disorder of the oral mucosa. We aimed to evaluate the clinical outcome of oral leukoplakia treated with several types of lasers and with the use of quantic molecular resonance (QMR) lancet, in terms of recurrence rate.

MATERIAL AND METHODS

Eighty-seven previously untreated OL (52 occurring in females and 35 in males, mean age of 59.4 ± 13.9 years) were consecutively submitted to surgical treatment at University Hospital of Parma, Italy, and Hospital de Valongo, Portugal, (1999 to 2012). Interventions were subclassified into 5 groups according to the instrument used for the surgical removal of OL (cold blade - 17; Nd:YAG 1064nm laser - 14; Er:YAG 2940nm laser - 33; CO2 10600nm laser - 15; and QMR scalpel - 8). The mean follow-up period after treatment was 21.6 months (range 1-151 months). The outcome of treatment was scored through the same clinical protocol in the two participating units. Statistical analysis were carried by univariate analysis using chi-square test (or Pearson's test when appropriate).

RESULTS

Recurrences were observed in 24 cases of OL (27.6%). Malignant transformation occurred in one patient (1.1%) after a period of 35 months. Statistical comparison of the 5 surgical treatment modalities showed no differences in clinical outcomes nor in the recurrence rate of OL. However, when Er:YAG laser group was compared with traditional scalpel, a significantly better outcome in cases treated with Er:YAG laser (P = 0.015) was highlighted.

CONCLUSIONS

Our results suggests that Er:YAG laser could be a promising option for the treatment of OL.

Flexible nanofilms coated with aligned piezoelectric microfibers preserve the contractility of cardiomyocytes

The use of engineered cardiac tissue for high-throughput drug screening/toxicology assessment remains largely unexplored. Here we propose a scaffold that mimics aspects of cardiac extracellular matrix while preserving the contractility of cardiomyocytes. The scaffold is based on a poly(caprolactone) (PCL) nanofilm with magnetic properties (MNF, standing for magnetic nanofilm) coated with a layer of piezoelectric (PIEZO) microfibers of poly(vinylidene fluoride-trifluoroethylene) (MNF+PIEZO). The nanofilm creates a flexible support for cell contraction and the aligned PIEZO microfibers deposited on top of the nanofilm creates conditions for cell alignment and electrical stimulation of the seeded cells. Our results indicate that MNF+PIEZO scaffold promotes rat and human cardiac cell attachment and alignment, maintains the ratio of cell populations overtime, promotes cell-cell communication and metabolic maturation, and preserves cardiomyocyte (CM) contractility for at least 12 days. The engineered cardiac construct showed high toxicity against doxorubicin, a cardiotoxic molecule, and responded to compounds that modulate CM contraction such as epinephrine, propranolol and heptanol.

Severe Mental Illness and Cancer – A Program for Psychiatric Patients in a Cancer Center

Introduction

The prevalence of severe mental illness (SMI) is estimated to be 4%. There are increased risk factors for cancer in SMI patients. People with SMI have deficient access and referral to routine cancer screening and psychiatric illness is often associated to late oncological diagnosis.

Objectives

Characterize the population of SMI patients that undergoes oncological treatment; establish a comparison with the general population in terms of stage at the time of diagnosis and the type of follow-up that ensued; characterize the psychiatric care available to these patients; propose the necessary changes to ensure adequate healthcare for SMI patients.

Aims

To assess and improve the quality of oncological care for SMI patients in our hospital.

Methods

We analyzed the data from SMI patients suffering from SMI observed by our group during a 12 month period.

Results

Low percentage of SMI patients being treated in our center regarding general rates; surprisingly high referral time to psychiatry unity; good compliance with treatments and appointments; have mostly been submitted to the standard oncological protocols of treatment.

Conclusion

In spite of serious psychiatric co-morbidity and psychosocial deficits, our SMI patients are able for standard cancer treatment and present sufficient compliance. We value the help of family members and social workers. We have to insist in educational sessions and psychiatric screening procedures for oncological teams. It is also fundamental to implement educational programs for mental health centers in Lisbon in order to sensitize for cancer risks among SMI and alert for the pivotal role of mental health staff, namely the psychiatrists.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Cysticercosis of the Brain

Incidence and radiologic findings of neurocysticercosis were investigated in a series of 23 800 consecutive head examinations using computed tomography (CT). The condition was diagnosed in 168 cases (0.7%). The parenchymatous form was the most common presentation (96.3%), while the meningeal form corresponded to only 11.9 per cent of cases. These two forms coexisted in some cases. These findings reversed the knowledge on the condition based on conventional radiography. The different CT appearances in the brain are described and a new radiologic protocol for the CT evaluation of the condition is advocated, which includes a follow-up after a trial cure with Praziquantel in the presence of cysts not associated with suggestive brain calcifications. CT was more sensitive than conventional radiography in the differentiation between dead and living larvae, thus having an impact on the therapeutic management of the patients.

Detection of the posterior superior alveolar artery in the lateral sinus wall using computed tomography/cone beam computed tomography: a prevalence meta-analysis study and systematic review

A systematic search of MEDLINE, Embase, and Proceedings Web of Science was undertaken to assess the prevalence of the posterior superior alveolar artery (PSAA) in the lateral sinus wall in sinus lift patients, as identified using computed tomography (CT)/cone beam computed tomography (CBCT). For inclusion, the article had to report PSAA detection in the bony wall using CT and/or CBCT in patients with subsinus edentulism. Studies on post-mortem findings, mixed samples (living and cadaveric), those presenting pooled results only, or studies performed for a sinus pathology were excluded. Heterogeneity was checked using an adapted version of the DerSimonian and Laird Q test, and quantified by calculating the proportion of the total variance due to between-study variance (Ri statistic). Eight hundred and eleven single papers were reviewed and filtered according to the inclusion/exclusion criteria. Ten studies were selected (1647 patients and 2740 maxillary sinuses (study unit)). The pooled prevalence of PSAA was 62.02 (95% confidence interval (CI) 46.33-77.71). CBCT studies detected PSAA more frequently (78.12, 95% CI 61.25-94.98) than CT studies (51.19, 95% CI 42.33-60.05). Conventional CT revealed thicker arteries than CBCT. It is concluded that PSAA detection is more frequent when CBCT explorations are used. Additional comparative studies controlling for potential confounding factors are needed to ascertain the actual diagnostic value of radiographic explorations for assessing the PSAA prior to sinus floor elevation procedures.

Effects of emotional valence and three-dimensionality of visual stimuli on brain activation: an fMRI study

BACKGROUND

Examining changes in brain activation linked with emotion-inducing stimuli is essential to the study of emotions. Due to the ecological potential of techniques such as virtual reality (VR), inspection of whether brain activation in response to emotional stimuli can be modulated by the three-dimensional (3D) properties of the images is important.

OBJECTIVE

The current study sought to test whether the activation of brain areas involved in the emotional processing of scenarios of different valences can be modulated by 3D. Therefore, the focus was made on the interaction effect between emotion-inducing stimuli of different emotional valences (pleasant, unpleasant and neutral valences) and visualization types (2D, 3D). However, main effects were also analyzed.

METHODS

The effect of emotional valence and visualization types and their interaction were analyzed through a 3 × 2 repeated measures ANOVA. Post-hoc t-tests were performed under a ROI-analysis approach.

RESULTS

The results show increased brain activation for the 3D affective-inducing stimuli in comparison with the same stimuli in 2D scenarios, mostly in cortical and subcortical regions that are related to emotional processing, in addition to visual processing regions.

CONCLUSIONS

This study has the potential of clarify brain mechanisms involved in the processing of emotional stimuli (scenarios' valence) and their interaction with three-dimensionality.

Effect of bariatric surgery on weight loss, inflammation, iron metabolism, and lipid profile

BACKGROUND AND AIMS

Accumulating evidence indicates that a state of chronic inflammation has a crucial role in the pathogenesis of obesity-related metabolic dysfunction. This study aims to evaluate changes in inflammatory process, iron metabolism, erythropoiesis, and lipid profile associated with weight loss after gastric banding surgery.

MATERIAL AND METHODS

A total of 46 patients were evaluated before and 3 months after gastric banding surgery. A survey was conducted to record demographic data, body mass index, and presence of comorbidities. Moreover, complete blood cell counts and serum levels of iron, ferritin, transferrin, high-sensitivity C-reactive protein, total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, and triglycerides were performed.

RESULTS

At a follow-up 3 months after surgery, our patients presented a significant decrease in weight and body mass index, associated with a decreased inflammatory process (decreased high-sensitivity C-reactive protein, neutrophil counts, and neutrophil:lymphocyte ratio), increased iron availability (increased transferrin saturation and a trend to higher iron serum levels), and significant decreased triglycerides and triglycerides:high-density lipoprotein-cholesterol ratio.

CONCLUSIONS

Our results showed a significant decrease in the inflammation process 3 months after gastric banding surgery, associated with adipose tissue loss. This decrease in the inflammatory process is associated with more efficient iron absorption and increased iron availability for erythropoiesis. Moreover, we also found decreased triglyceride serum levels. These changes suggest benefits of weight loss, including decreased risk of cardiovascular disease.

Association between allergies and multiple sclerosis: a systematic review and meta-analysis

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system that expresses a typical type 1 immune response (Th1). Allergies, on the other hand, present with high levels of type 2 (Th2) cytokines. Some authors observed that Th1 and Th2 diseases could coexist in the same subject. Besides its biological plausibility, the association between MS and allergies remains controversial. The aim of this systematic review and meta-analysis was to determine if there is an association between allergic diseases and MS. All clinical and epidemiological studies on patients with MS published up to July 2009, that assessed the association between allergic diseases and MS were reviewed. A total of 1010 articles were retrieved from search, and ten epidemiological studies were included in the analysis. The results showed that there is no evidence supporting an association between allergic diseases (OR: 0.91; CI 95%: 0.68-1.23), asthma (OR: 0.83; CI 95%: 0.48-1.44), allergic rhinitis (OR: 0.81; CI 95%: 0.59-1.12), eczema (OR: 0.93; CI 95%: 0.71-1.23) and MS. Additional prospective studies in this field might help to elucidate the nature of these associations.

Protective role of the HLA–A*02 allele in Portuguese patients with multiple sclerosis

Background

Multiple sclerosis (MS) is associated with human leukocyte antigen (HLA) HLA–DRB1*15. Recent evidence that CD8 T cells are implicated in MS suggests that HLA class I may also contribute. An association of HLA–A*02 and A*03 alleles has been described.

Objectives

We examined the influence of HLA–A*02 and HLA–A*03 in Portuguese patients with MS, independently of HLA–DRB1*15 using a logistic regression model.

Conclusions

DRB1*15 increased the risk of developing MS and HLA–A*02 decreased the risk. A*03 had no effect. To analyze if HLA–A*02 association was independent from DRB1*15, an interaction between these two alleles was introduced in the model; no significant interaction was found.

Classification of endoscopic capsule images by using color wavelet features, higher order statistics and radial basis functions

This paper presents a system to support medical diagnosis and detection of abnormal lesions by processing capsule endoscopic images. Endoscopic images possess rich information expressed by texture. Texture information can be efficiently extracted from medium scales of the wavelet transform. The set of features proposed in this paper to code textural information is named color wavelet covariance (CWC). CWC coefficients are based on the covariances of second order textural measures, an optimum subset of them is proposed. Third and forth order moments are added to cope with distributions that tend to become non-Gaussian, especially in some pathological cases. The proposed approach is supported by a classifier based on radial basis functions procedure for the characterization of the image regions along the video frames. The whole methodology has been applied on real data containing 6 full endoscopic exams and reached 95% specificity and 93% sensitivity.

Different modes of inhibition of mouse Cyp2a5 and rat CYP2A3 by the food-derived 8-methoxypsoralen

CYP2A enzymes are responsible for nicotine metabolism and for activating tobacco-related carcinogens. Inhibition of CYP2A is a promising approach in chemoprevention, which could lead to a decrease in cigarette consumption and to a reduction in tobacco-related cancer risk. 8-Methoxypsoralen (8-MOP) is a mechanism-based inhibitor of human CYP2A6 and CYP2A13. 8-MOP is also an inhibitor of Cyp2a5, but the mode of this inhibition is unknown. There is no published data on the inhibition of CYP2A3 by 8-MOP. The objective of this work was to investigate the characteristics of 8-MOP inhibition on mouse hepatic Cyp2a5 and rat nasal CYP2A3, in order to determine the best experimental model for chemoprevention studies using 8-MOP. The results show that 8-MOP inhibits CYP2a5 through three different mechanisms: competitive, non-competitive (K(iu)=1.7 microM), and mechanism-based (K(inactivation) of 0.17 min(-1)). By contrast, 8-MOP was able to inhibit CYP2A3-mediated coumarin 7-hydroxylase only in a non-competitive way (K(iu)=0.22 microM). In conclusion, we showed that 8-MOP inhibits Cyp2a5 and CYP2A3 through different mechanisms.

Intragastric balloon for obesity

BACKGROUND

Obesity is one of the major public health problems of modern society. Intragastric balloon (IGB) treatment for obesity has been developed as a temporary aid. Its primary objective is the treatment of obese people, who have had unsatisfactory results in their clinical treatment for obesity, despite of being cared for by a multidisciplinary team, and super obese patients with a higher surgical risk. However, the effects of different IGB procedures compared with conventional treatments and with each other are uncertain.

OBJECTIVES

To assess the effects of intragastric balloon in people with obesity.

SEARCH STRATEGY

Studies were obtained from computerised searches of MEDLINE, EMBASE, LILACS, The Cochrane Library and other electronic databases. Furthermore, reference lists of relevant articles and hand searches of selected journals were performed. Experts in the field were contacted.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials fulfilling the inclusion criteria were used. Short term weight loss is common, so studies were included if they reported measurements after a minimum of four weeks follow-up.

DATA COLLECTION AND ANALYSIS

Data were extracted by one reviewer and checked independently by two reviewers. Two reviewers independently assessed the quality of trials.

MAIN RESULTS

Nine randomised controlled trials involving 395 patients were included. Six out of nine studies had a follow-up of less than one year, the longest study duration was 24 months. Only a third of the analysed studies revealed a low risk of bias. No information was available on quality of life, all-cause mortality and morbidity. Compared with conventional management, IGB did not show convincing evidence of a greater weight loss. On the other hand, complications of intragastric balloon placement occurred, however few of a serious nature. The relative risks for minor complications like gastric ulcers and erosions were significantly raised.

AUTHORS' CONCLUSIONS

Evidence from this review is limited for decision making, since there was large heterogeneity in IGB trials, regarding both methodological and clinical aspects. However, a co-adjuvant factor described by some authors in the loss and maintenance of weight has been the motivation and the encouragement to changing eating habits following a well-organized diet and a program of behavioural modification. The IGB alone and the technique of positioning appear to be safe. Despite the evidence for little additional benefit of the intragastric balloon in the loss of weight, its cost should be considered against a program of eating and behavioural modification.

Helicobacter pylori virulence genotypes in Portuguese children and adults with gastroduodenal pathology

The aim of this study was to evaluate the prevalence of virulence genotypes, namely cagA, vacA and babA2, of Helicobacter pylori strains isolated from Portuguese adults and children presenting gastroduodenal pathology. One hundred thirty-six strains were studied, 82 isolated from adult patients (50 with nonulcerative gastritis and 32 with active peptic ulcer) and 58 isolated from children (54 with nonulcerative gastritis and 4 with duodenal ulcer). Genotyping of cagA, vacA and babA2 was assessed by polymerase chain reaction. Overall, Helicobacter pylori strains carrying more virulent genotypes were much more prevalent in adults than in children, particularly the type I ( vacAs1- and cagA-positive) and the triple-positive ( vacAs1-, cagA- and babA2-positive) strains ( P<0.001). A subpopulation of adults and children with nonulcerative gastritis was also studied, and differences in the prevalence of virulent genotypes were observed, either for individual genotypes ( P=0.017 for cagA, P=0.010 for vacAs1) or in combinations, i.e. the type I genotype ( P=0.005) and the triple-positive strains ( P=0.031). There was no difference between the two populations in the distribution of babA2 and m1/m2 genotypes. Considering the cohort effect in the epidemiology of Helicobacter pylori infection, these results suggest that different strains might circulate during different periods of time, or that, after infection in childhood, individual strains will undergo changes during the course of infection.

Increase of arterial thrombosis parameters in chronic Helicobacter pylori infection in mice

An animal model was developed to study arterial thrombosis and determine if animals infected with Helicobacter pylori behave differently after induction of direct damage to blood vessels. Twenty-one C56/BL6 mice inoculated with the "Sydney strain" of H. pylori and 19 uninfected animals were kept for 1 year before testing. Vascular lesions were induced to mesenteric arterioles (15-25 microm diameter) by Argon laser. The dynamic course of thrombus formation was continuously monitored by a video camera for 10 min. Three parameters were assessed: (1) the number of laser pulses required to induce thrombus formation, (2) the number of platelet emboli removed by the blood flow and, (3) the duration of embolization. Additionally, blood was tested for platelet aggregation, fibrinogen, and cell count. Of the parameters measured, statistical differences between infected and uninfected mice concerned the number of emboli formed (6.00+/-2.18 infected vs. 3.89+/-1.37 non-infected, p=.0006) and the duration of embolization (2.41+/-0.73 min infected vs. 1.47+/-0.61 min non-infected p>.0001). A significant difference was also found in the fibrinogen levels between infected and uninfected mice. Chronic infection of mice with H. pylori leads to increased platelet embolization after damage to arterioles. These results are in favor of the possible involvement of H. pylori infection in the acute phase of coronary heart disease (CHD).

Evaluation of the performance of the Helico Blot 2.1 as a tool to investigate the virulence properties of Helicobacter pylori

Knowledge of the cagA status of Helicobacter pylori infection could be relevant for the treatment and prevention of possible complications of infection. This goal can be achieved using serology since CagA is highly immunogenic. The aim of this study was to correlate the presence of the cagA gene detected by polymerase chain reaction (PCR) with the presence of serum antibodies against the CagA protein using a recently available commercial immunoblotting assay, the Helico Blot 2.1 kit. Considering the results obtained by PCR, Helico Blot 2.1 presented sensitivity, specificity, and positive and negative predictive values for CagA status of 97.4%, 87.7%, 80.9% and 98.5%, respectively.

Magnetic immuno-PCR assay with inhibitor removal for direct detection of Helicobacter pylori in human feces

A PCR protocol was developed to detect Helicobacter pylori in human stool specimens. This protocol was based on the association of a magnetic immuno-PCR assay with a technique to remove inhibitors (agarose-embedded DNA preparation). Of the 47 H. pylori-positive and 57 H. pylori-negative patients included in this study, 38 were positive and 66 were negative by this new protocol. The sensitivity, specificity, and predictive values for a positive or a negative result were 80.9% (95% confidence interval [CI], 66.3 to 90.4), 100% (95% CI, 92.1 to 100), 100% (95% CI, 88.6 to 100), and 86.4% (95% CI, 75.2 to 93.2), respectively.

Detection of Helicobacter pylori DNA in human feces by PCR: DNA stability and removal of inhibitors

In this study, the stability of Helicobacter pylori DNA in human feces and the effect of a diet lacking in plant material, the suspected source of PCR inhibitors in human feces, were investigated. In addition, a method to remove these inhibitors was developed. Stools inoculated with H. pylori were used as a model. For this purpose, a H. pylori suspension (10(8) CFU/ml) was used to spike stool samples obtained from four healthy adults known to be H. pylori negative. The evaluation of the stability of H. pylori DNA in feces showed that DNA was degraded after 3 days of contact with fecal material at 37 degrees C. A 2-day diet completely free of plant material was sufficient to eliminate PCR inhibitors from human feces. However, inhibitors were detected 48 h after a normal diet was resumed. A new technique consisting of agarose blocks containing embedded DNA as a template for PCR amplification was used for removal of inhibitors, following DNA extraction by a modified QIAamp tissue method (Qiagen, Hilden, Germany). When this method was applied to inhibiting stool samples known to have an inhibitory effect and spiked with H. pylori (5.10(8) CFU/g), a positive PCR was obtained showing that inhibitors present in the original DNA samples were completely removed. The agarose embedded DNA block method is highly efficient and provides clean, high quality template DNA for PCR purposes avoiding long and fastidious conventional extraction methods. In conclusion, this study confirms that H. pylori DNA degrades with time in stools. A diet free of plant material or a special DNA preparation can be used to remove inhibitors and to allow the detection of H. pylori.

[How to determine the diagnosis of Helicobacter pylori infection in the elderly?]

PURPOSE

The real prevalence of Helicobacter pylori (H. pylori) infection is difficult to determine in the elderly because of the frequency of drug intake (antibiotics or anti-secretory drugs). The aim of this study was to evaluate the diagnostic performance of five tests in the elderly.

METHODS

The study population consisted of consecutive patients undergoing a routine endoscopy between August 1998 and December 1999. We evaluated the diagnostic performance of four tests in all of the included patients: culture and histology of biopsy specimens, serology (ELISA) and urea breath test (13C-UBT). Detection of H. pylori antigens in stool samples (HpSA) was realized in a subgroup. Patients were considered H. pylori + when result for culture was positive or when two tests were positive.

RESULTS

One hundred and sixty-seven patients were included in this study (55 men, 112 women; mean age: 85.6 +/- 5.1 years). Only 38 (22.8%) patients were H. pylori+. Test performances showed the following results: serology sensitivity: 90.9% (IC 95%: 75.6-98.1) versus 86.9% (IC 95%: 63.6-96.9) for culture versus 77.8% (IC 95%: 60.8-89.9) for histology and 74.3% (IC 95%: 56.7-87.5) for 13C-UBT. Eighty-nine (53.3%) took antibiotics or anti-secretory drugs, only 13C-UBT performances decreased significantly (sensitivity: 94.4% [72.7-99.8] versus 52.9% [27.8-77]; P < 10(-6)). When gastric or duodenal ulcer were endoscopically diagnosed in older patients, both histology and 13C-UBT could not improve the diagnosis of H. pylori infection. HpSA was realized in 107 patients (sensitivity: 74.1%, specificity: 98.7%). We showed no statistical difference between HpSA performances and drug intake.

CONCLUSION

Diagnostic performances decreased in older patients especially because of drug intake.

Diagnosis of Helicobacter pylori infection: noninvasive methods compared to invasive methods and evaluation of two new tests

OBJECTIVES

Current guidelines recommending Helicobacter pylori eradication treatment without performing endoscopy in certain patients highlight the importance of noninvasive tests. Our aim was to determine the accuracy of two new tests: the antigen stool test and Helicoblot 2.1 (an immunoblot used on serum) as well as the 13C urea breath test and ELISA serology in comparison to invasive tests for the pretreatment diagnosis of H. pylori infection.

METHODS

Helicobacter pylori infection was diagnosed prospectively in 104 untreated patients using eight different tests. Invasive tests included culture, urease test (CLOtest), histology, and PCR; noninvasive tests included the 13C urea breath test, IgG serology (Pyloriset EIA-G), immunoblot (Helicoblot 2.1), and antigen stool detection (Premier Platinum HpSA). A predefined gold standard based on biopsy tests was used to define H. pylori status, as well as an empirical approach.

RESULTS

There was no statistically significant difference between the different tests. The sensitivity of the noninvasive tests ranged between 88.9% and 95.6% (stool test: 88.9%, 95% CI: 82.7-95.1, and Helicoblot 2.1: 95.6%, 95% CI: 91.5-99.6) and the specificity ranged between 92.6 and 98.1% (stool test: 94.4%, 95% CI: 84.6-98.8, and Helicoblot 2.1: 92.6%, 95% CI: 91.5-96.2) when a predefined gold standard was used.

CONCLUSIONS

Most tests had sensitivities, specificities, and predictive values >90%. The noninvasive tests are accurate for the diagnosis of H. pylori infection. Helicoblot 2.1 performed as well as the best ELISA kit. The HpSA is a promising direct noninvasive test that can be applied easily to evaluate H. pylori status.

Detection of Helicobacter species in the liver of patients with and without primary liver carcinoma

BACKGROUND

Several studies have shown the presence of Helicobacter species in the human biliary tract and in the intestinal tract of animals. In this study, the presence of Helicobacter species in liver samples from patients with primary hepatic carcinomas was evaluated.

METHODS

Sixteen liver specimens were studied (8 from patients with primary liver carcinoma and 8 from patients without primary liver carcinoma). Histology with standard stains, culture, and polymerase chain reaction (PCR) amplification using two sets of primers located in the 16S ribosomal DNA (rDNA) were used to detect the presence of bacteria. Amplified products were sequenced to determine the genus and species of the bacteria. A search for other genes that were specific for Helicobacter pylori also was carried out by PCR.

RESULTS

PCR performed with the 16S rDNA primers revealed the presence of bacteria from the genus Helicobacter in all of the liver specimens from patients with primary liver carcinoma (eight of eight patients) and in one specimen from a patient without primary liver carcinoma (one of eight patients). When the nucleotide sequence of > 80% of the 16S rDNA was determined, the closest similarity was with the 16S rDNA from H. pylori in eight patients. In 1 patient sample from which only 398 nucleotides were sequenced, the closest match was Helicobacter felis.

CONCLUSIONS

The results presented in this study indicate that Helicobacter species can be present in the liver of patients with primary hepatic carcinoma, but their eventual role in the carcinogenesis process, although it is plausible, remains to be proven. Based on sequence similarity, it seems that Helicobacter species that are related closely to H. pylori but are distinct from it have been found.

Detection of Helicobacter species in the liver of patients with and without primary liver carcinoma

BACKGROUND

Several studies have shown the presence of Helicobacter species in the human biliary tract and in the intestinal tract of animals. In this study, the presence of Helicobacter species in liver samples from patients with primary hepatic carcinomas was evaluated.

METHODS

Sixteen liver specimens were studied (8 from patients with primary liver carcinoma and 8 from patients without primary liver carcinoma). Histology with standard stains, culture, and polymerase chain reaction (PCR) amplification using two sets of primers located in the 16S ribosomal DNA (rDNA) were used to detect the presence of bacteria. Amplified products were sequenced to determine the genus and species of the bacteria. A search for other genes that were specific for Helicobacter pylori also was carried out by PCR.

RESULTS

PCR performed with the 16S rDNA primers revealed the presence of bacteria from the genus Helicobacter in all of the liver specimens from patients with primary liver carcinoma (eight of eight patients) and in one specimen from a patient without primary liver carcinoma (one of eight patients). When the nucleotide sequence of > 80% of the 16S rDNA was determined, the closest similarity was with the 16S rDNA from H. pylori in eight patients. In 1 patient sample from which only 398 nucleotides were sequenced, the closest match was Helicobacter felis.

CONCLUSIONS

The results presented in this study indicate that Helicobacter species can be present in the liver of patients with primary hepatic carcinoma, but their eventual role in the carcinogenesis process, although it is plausible, remains to be proven. Based on sequence similarity, it seems that Helicobacter species that are related closely to H. pylori but are distinct from it have been found.

Near infrared spectroscopy-measured changes in cerebral blood volume and cytochrome aa3 in newborn lambs exposed to hypoxia and hypercapnia, and ischemia: a comparison with changes in brain perfusion and O2 metabolism

OBJECTIVES

Validation of near infrared spectroscopy (NIRS)-measured changes in cerebral blood volume (deltaCBV) and cytochrome aa3 (deltaCytaa3) as estimators of changes in brain perfusion and oxygenation in the newborn lamb during hypoxia and hypercarbia, and additional hypotension.

METHODS AND MATERIALS

In 33 newborn lambs brain perfusion assessed by carotid artery blood flow (deltaQcar: ml/min)and cerebral metabolic rate of oxygen (deltaCMRO2: ml O2/min) were related to NIRS-derived deltaCBV (ml/100 g) and deltaCytaa3 (microM) during combined hypoxia and hypercarbia and additional hypotension. Combined hypoxia and hypercapnia was induced by ventilation with 6-8% of O2 and 10% of CO2 during 30 min, and additional hypotension ( < 35 mmHg for 5 min) was induced by careful withdrawal of blood.

RESULTS

CBV increased during hypoxia and hypercarbia, decreased during additional hypotension and was related to deltaQcar: (0.009 ml/100 g change per ml/min Qcar: P < 0.0001). Cytaa3 increased during hypoxia and hypercarbia, decreased during subsequent additional hypotension andshowed a reverse relationship with deltaCMRO2 (-1.65 microM change per ml O2/min CMRO2: P <0.0001). Cytaa3 remained above baseline during reperfusion.

CONCLUSIONS

deltaCBV estimates changes in brain perfusion, but overestimates brain perfusion during hypotension. The pattern of deltaCytaa3 suggests less oxygen utilisation by brain tissue during hypoxia and subsequent reperfusion.

Direct detection of Helicobacter pylori resistance to macrolides by a polymerase chain reaction/DNA enzyme immunoassay in gastric biopsy specimens

BACKGROUND

The increasing use of macrolides especially in the treatment of Helicobacter pylori infection has led to an increase in resistant strains. The resistance of H pylori to macrolides, especially clarithromycin, is one of the major causes of eradication failure. In H pylori, clarithromycin resistance is due to point mutations localised in domain V of 23S rRNA.

AIM

To develop a molecular technique based on amplification of a relevant fragment of the 23S rRNA and colorimetric hybridisation in liquid phase to detect directly in biopsy specimens the type of mutation associated with resistance of H pylori to clarithromycin.

METHODS

Gastric biopsy samples from 61 patients were submitted to this test. The results were compared with standard methods (determination of minimal inhibition concentration, polymerase chain reaction/restriction fragment length polymorphism, and/or DNA sequencing) in order to evaluate the test and to define the cut off values, specificity, and sensitivity.

RESULTS

The 14 biopsy samples in which H pylori was not detected did not give a positive result in any assay, and the 14 samples harbouring strains susceptible to clarithromycin gave a positive result with the wild type probe as expected. The 33 biopsy specimens containing resistant strains always gave a positive signal with one of the probes detecting resistant organisms, but in eight cases they also reacted with the wild type probe, indicating that a mixture of resistant and susceptible organisms was present.

CONCLUSION

The importance of this new assay is that it allows the detection of multiple genotypes corresponding to either heterogeneous genotypes or mixed infections. Moreover, it allows in a single step not only the detection of H pylori but also the determination of its susceptibility to clarithromycin directly in biopsy specimens without the need for culture.

Collaborative study to improve the quality control of rare earth element determinations in environmental matrices

In order to control the quality of rare earth determinations in environmental matrices, the Standards, Measurements and Testing Programme (formerly Community Bureau of Reference, BCR) of the European Commission has started a project, the final aim of which is to certify four types of matrices (tuna muscle, mussel tissue, aquatic plant and estuarine sediment) for their contents of a range of rare earth elements (Sc, Y and the lanthanides: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu). The elements U and Th were added to the study. The first part of this project consisted of an interlaboratory study which aimed to test the feasibility of preparation of environmental reference materials and to detect and remove most of the pitfalls observed in rare earth determinations. This paper presents the preparation of the four matrices for the intercomparison study and for the candidate reference material. The main results are presented of the interlaboratory study that was carried out prior to the certification campaign. This collaborative trial is the first attempt ever carried out at this scale to evaluate the state-of-the-art of rare earth determinations in the environment. Its impact on the improvement of chemical measurements will have positive effects on the comparability of data necessary for environmental monitoring.