Identification of TGFß signatures in six murine models mimicking different osteoarthritis clinical phenotypes.

OBJECTIVE: TGFß is a key player in cartilage homeostasis and OA pathology. However, few data are available on the role of TGFß signalling in the different OA phenotypes. Here, we analysed the TGFß pathway by transcriptomic analysis in six mouse models of OA. METHOD: We have brought together seven expert laboratories in OA pathophysiology and, used inter-laboratories standard operating procedures and quality controls to increase experimental reproducibility and decrease bias. As none of the available OA models covers the complexity and heterogeneity of the human disease, we used six different murine models of knee OA: from post-traumatic/mechanical models (meniscectomy (MNX), MNX and hypergravity (HG-MNX), MNX and high fat diet (HF-MNX), MNX and seipin knock-out (SP-MNX)) to aging-related OA and inflammatory OA (collagenase-induced OA (CIOA)). Four controls (MNX-sham, young, SP-sham, CIOA-sham) were added. OsteoArthritis Research Society International (OARSI)-based scoring of femoral condyles and ribonucleic acid (RNA) extraction from tibial plateau samples were done by single operators as well as the transcriptomic analysis of the TGFß family pathway by Custom TaqMan® Array Microfluidic Cards. RESULTS: The transcriptomic analysis revealed specific gene signatures in each of the six models; however, no gene was deregulated in all six OA models. Of interest, we found that the combinatorial Gdf5-Cd36-Ltbp4 signature might discriminate distinct subgroups of OA: Cd36 upregulation is a hallmark of MNX-related OA while Gdf5 and Ltbp4 upregulation is related to MNX-induced OA and CIOA. CONCLUSION: These findings stress the OA animal model heterogeneity and the need of caution when extrapolating results from one model to another.

Review article: moving towards common therapeutic goals in Crohn's disease and rheumatoid arthritis.

BACKGROUND: Crohn's disease (CD) and rheumatoid arthritis are chronic, progressive and disabling conditions that frequently lead to structural tissue damage. Based on strategies originally developed for rheumatoid arthritis, the treatment goal for CD has recently moved from exclusively controlling symptoms to both clinical remission and complete mucosal healing (deep remission), with the final aim of preventing bowel damage and disability. AIM: To review the similarities and differences in treatment goals between CD and rheumatoid arthritis. METHODS: This review examined manuscripts from 1982 to 2016 that discussed and/or proposed therapeutic goals with their supportive evidence in CD and rheumatoid arthritis. RESULTS: Proposed therapeutic strategies to improve outcomes in both rheumatoid arthritis and CD include: (i) evaluation of musculoskeletal or organ damage and disability, (ii) tight control, (iii) treat-to-target, (iv) early intervention and (v) disease modification. In contrast to rheumatoid arthritis, there is a paucity of disease-modification trials in CD. CONCLUSIONS: Novel therapeutic strategies in CD based on tight control of objective signs of inflammation are expected to change disease course and patients' lives by halting progression or, ideally, preventing the occurrence of bowel damage. Most of these strategies require validation in prospective studies, whereas several disease-modification trials have addressed these issues in rheumatoid arthritis over the last decade. The recent approval of new drugs in CD such as vedolizumab and ustekinumab should facilitate initiation of disease-modification trials in CD in the near future.

Pain expectations in neuropathic pain: Is it best to be optimistic?

BACKGROUND: Pain expectancy may be an important variable that has been found to influence the effectiveness of treatments for pain. Much of the literature supports a self-fulfilment perspective where expectations for pain relief predict the actual pain experienced. However, in conditions such as neuropathic pain (NeP) where pain relief is difficult to attain, expectations for pain relief could be unrealistic. The objective of this study was to investigate the relationship between realistic/unrealistic expectations and 6-month, post-treatment outcomes. METHODS: We performed a retrospective analysis of a large cohort of patients with NeP (n = 789) attending tertiary care centres to determine the association between unrealistic (both positive and negative) and realistic expectations with outcomes after multidisciplinary treatment. An expectation variable with three categories was calculated: realistic expectations were those whose expected reduction in pain was similar to the observed mean group reduction in pain, while optimistic and pessimistic expectations were those who over- or under-estimated the expected response to treatment, respectively. The association between baseline realistic/unrealistic expectations and 6-month pain-related disability, catastrophizing and psychological distress was assessed. RESULTS: Univariable analyses suggested that realistic expectations were associated with lower levels of disability, catastrophizing and psychological distress, compared to unrealistic expectations. However, after adjustment for baseline symptom severity, multivariable analysis revealed that patients with optimistic expectations had lower levels of disability, than those with realistic expectations. Those with pessimistic expectations had higher levels of catastrophizing and psychological distress at follow-up. CONCLUSIONS: These findings are largely congruent with the self-fulfilment perspective to expectations. SIGNIFICANCE: This study defined realistic pain expectations with patient data. Examining the relationship between expectations between pain and disability in a large cohort of patients with neuropathic pain.

The CanPain SCI Clinical Practice Guidelines for Rehabilitation Management of Neuropathic Pain after Spinal Cord: introduction, methodology and recommendation overview.

STUDY DESIGN: Clinical practice guidelines. OBJECTIVES: The objective was to develop the first Canadian clinical practice guidelines for the management of neuropathic pain in people with spinal cord injury (SCI). SETTING: The guidelines are relevant for inpatient and outpatient SCI rehabilitation settings in Canada. METHODS: The guidelines were developed in accordance with the Appraisal of Guidelines for Research and Evaluation II tool. A Steering Committee and Working Group reviewed the relevant evidence on neuropathic pain management (encompassing screening and diagnosis, treatment and models of care) after SCI. The quality of evidence was scored using Grading of Recommendations Assessment, Development and Evaluation (GRADE). A consensus process was followed to achieve agreement on recommendations and clinical considerations. RESULTS: The Working Group developed 12 recommendations for screening and diagnosis, 12 recommendations for treatment and 5 recommendations for models of care. Important clinical considerations accompany each recommendation. CONCLUSIONS: The Working Group recommendations for the management of neuropathic pain after SCI should be used to inform practice.

The CanPain SCI Clinical Practice Guidelines for Rehabilitation Management of Neuropathic Pain after Spinal Cord: Recommendations for treatment.

STUDY DESIGN: Clinical practice guidelines. OBJECTIVES: To develop the first Canadian clinical practice guidelines for treatment of neuropathic pain in people with spinal cord injury (SCI). SETTING: The guidelines are relevant for inpatient and outpatient SCI rehabilitation settings in Canada. METHODS: The CanPainSCI Working Group reviewed the evidence for different treatment options and achieved consensus. The Working Group then developed clinical considerations for each recommendation. Recommendations for research are also included. RESULTS: Twelve recommendations were developed for the management of neuropathic pain after SCI. The recommendations address both pharmacologic and nonpharmacologic treatment modalities. CONCLUSIONS: An expert Working Group developed recommendations for the treatment of neuropathic pain after SCI that should be used to inform practice.

The CanPain SCI Clinical Practice Guideline for Rehabilitation Management of Neuropathic Pain after Spinal Cord: recommendations for model systems of care.

STUDY DESIGN: Clinical practice guidelines. OBJECTIVES: The project objectives were to develop the first Canadian recommendations on a model of care for the management of at- and below-level neuropathic pain in people with spinal cord injury (SCI). SETTING: The guidelines are relevant for inpatient and outpatient SCI rehabilitation settings in Canada. METHODS: On the basis of a review of the Accreditation Canada standards, the Steering Committee developed questions to guide the CanPainSCI Working Group when developing the recommendations. The Working Group agreed on recommendations through a consensus process. RESULTS: The Working Group developed five recommendations for the organization of neuropathic pain rehabilitation care in people with SCI. CONCLUSIONS: The Working Group recommendations for a model of care for at- and below-level neuropathic pain after SCI should be used to inform clinical practice.

The CanPain SCI Clinical Practice Guidelines for Rehabilitation Management of Neuropathic Pain after Spinal Cord: screening and diagnosis recommendations.

STUDY DESIGN: Clinical practice guidelines. OBJECTIVES: To develop the first Canadian clinical practice guidelines for screening and diagnosis of neuropathic pain in people with spinal cord injury (SCI). SETTING: The guidelines are relevant for inpatient and outpatient SCI rehabilitation settings in Canada. METHODS: The CanPainSCI Working Group reviewed evidence to address clinical questions regarding screening and diagnosis of neuropathic pain after SCI. A consensus process was followed to achieve agreement on recommendations and clinical considerations. RESULTS: Twelve recommendations, based on expert consensus, were developed for the screening and diagnosis of neuropathic pain after SCI. The recommendations address methods for assessment, documentation tools, team member accountability, frequency of screening and considerations for diagnostic investigation. Important clinical considerations accompany each recommendation. CONCLUSIONS: The expert Working Group developed recommendations for the screening and diagnosis of neuropathic pain after SCI that should be used to inform practice.

Impact on health-related quality of life and costs of managing chronic neuropathic pain in academic pain centres: Results from a one-year prospective observational Canadian study.

BACKGROUND: The management of chronic pain, including neuropathic pain (NeP), is a major public health issue. However, there is a paucity of data evaluating pain management strategies in real-life settings. OBJECTIVE: To inform policy makers about the economic value of managing chronic NeP in academic centres by conducting a subeconomic assessment of a Canadian multicentre cohort study aimed at determining the long-term outcomes of the management of chronic NeP in academic pain centres. Specific questions regarding the economic value of this type of program were answered by a subset of patients to provide further information to policy makers. METHODS: Baseline demographic information and several pain-related measurements were collected at baseline, three, six and 12 months in the main study. A resource use questionnaire aimed at determining NeP-related costs and the EuroQoL-5 Dimension were collected in the subset study from consenting patients. Statistical analyses were conducted to compare outcomes over time and according to responder status. RESULTS: A total of 298 patients were evaluated in the present economic evaluation. The mean (± SD) age of the participants was 53.7±14.0 years, and 56% were female. At intake, the mean duration of NeP was >5 years. Statistically significant improvements in all pain and health-related quality of life outcomes were observed between the baseline and one-year visits. Use decreased over time for many health care resources (eg, visits to the emergency room decreased by one-half), which resulted in overall cost savings. CONCLUSION: The results suggest that increased access to academic pain centres should be facilitated in Canada.

Neuropathic pain in a primary care electronic health record database.

BACKGROUND: Neuropathic pain (NP) is common in the adult population but is difficult to study in electronic health record (EHR) databases because it is a symptom rather than a pathologic diagnosis. The first step in studying NP in EHR databases is to develop methods for identifying patients with NP. The objectives of this study were to develop estimates of the prevalence of NP among patients in a primary care EHR database and describe these patients' demographic characteristics and health-care utilization. METHODS: This was a retrospective cohort study of de-identified data from a 5-year period (2005-2010) from 23 general practitioners (GPs) in 10 primary care practices in southwestern Ontario, Canada. International Classification of Diseases version 9 (ICD-9) diagnostic codes and medication prescriptions were used to identify patients with certain and probable NP. RESULTS: Different methods produced prevalence estimates ranging from 1.5% (for certain NP in the epidemiologically rigorous period cohort) to 11.2% (for certain NP + probable NP in the more inclusive database cohort). Patients in the NP groups had more GP visits, specialist referrals and analgesic prescriptions than patients without NP. CONCLUSION: This study represents a step towards being able to utilize EHR databases to study NP by proposing methods to identify patients with certain and probable NP in a primary care EHR database. Validation against a gold standard is the next step.

Oxidative stress-induced expression of HSP70 contributes to the inhibitory effect of 15d-PGJ2 on inducible prostaglandin pathway in chondrocytes.

The inhibitory effect of 15-deoxy-Δ(12,14)-prostaglandin J2 (15d-PGJ2) on proinflammatory gene expression has been extensively documented and frequently ascribed to its ability to prevent NF-κB pathway activation. We and others have previously demonstrated that it was frequently independent of the peroxisome proliferator activated receptor (PPAR)γ activation. Here, we provide evidence that induction of intracellular heat shock protein (HSP)70 by oxidative stress is an additional regulatory loop supporting the anti-inflammatory effect of 15d-PGJ2 in chondrocytes. Using real-time quantitative PCR and Western blotting, we showed that 15d-PGJ2 stimulated HSP70, but not HSP27 expression while increasing oxidative stress as measured by spectrofluorimetry and confocal spectral imaging. Using N-acetylcysteine (NAC) as an antioxidant, we demonstrated further that oxidative stress was thoroughly responsible for the increased expression of HSP70. Finally, using an HSP70 antisense strategy, we showed that the inhibitory effect of 15d-PGJ2 on IL-1-induced activation of the NF-κB pathway, COX-2 and mPGES-1 expression, and PGE2 synthesis was partly supported by HSP70. These data provide a new anti-inflammatory mechanism to support the PPARγ-independent effect of 15d-PGJ2 in chondrocyte and suggest a possible feedback regulatory loop between oxidative stress and inflammation via intracellular HSP70 up-regulation. This cross talk is consistent with 15d-PGJ2 as a putative negative regulator of the inflammatory reaction.

Association between adiponectin and cartilage degradation in human osteoarthritis.

OBJECTIVE: Conflicting findings raise questions about the role of adiponectin in osteoarthritis (OA). The current study aimed to investigate in OA patients the association between the production of adiponectin and the grade of cartilage destruction, and to provide functional evidence for a potential role of adiponectin in OA. DESIGN: The expression of adiponectin was examined by immunohistochemistry in cartilage obtained from healthy individuals (n = 2; ages 56 and 41 years; 1 male and 1 female) and OA patients (n = 11; ages 64-79 years; 2 male and 9 female). The association between its production in chondrocytes and the grade of cartilage destruction was established on full-depth cartilage biopsies. The functional activity of adiponectin in OA cartilage was determined from the relation between the expression of adiponectin, its receptor, cartilage-specific components and factors involved in matrix degradation, and from the chondrocyte response to the full-length or the globular form of adiponectin. RESULTS: Adiponectin was not detected in healthy cartilage. Conversely, the adipokine was up-regulated in damaged tissue, but no strong association with the grade of cartilage destruction was found. We showed a positive correlation between adiponectin and mPGES or MMP-13 while AdipoR1 was related to the expression of type 2 collagen, aggrecan and Sox9. The full-length form of adiponectin but not the globular isoform, stimulated the production of PGE2 and MMP-13 activity in cultured human chondrocytes. CONCLUSIONS: The elevated level of adiponectin found in chondrocytes from OA patients might contribute to matrix remodelling during OA, the full-length isoform being the single active form.

Establishing a multicentre clinical research network: lessons learned.

BACKGROUND: Within many health care disciplines, research networks have emerged to connect researchers who are physically separated, to facilitate sharing of expertise and resources, and to exchange valuable skills. A multicentre research network committed to studying difficult cancer pain problems was launched in 2004 as part of a Canadian initiative to increase palliative and end-of-life care research capacity. Funding was received for 5 years to support network activities. METHODS: Mid-way through the 5-year granting period, an external review panel provided a formal mid-grant evaluation. Concurrently, an internal evaluation of the network by survey of its members was conducted. Based on feedback from both evaluations and on a review of the literature, we identified several components believed to be relevant to the development of a successful clinical cancer research network. RESULTS: THESE COMMON ELEMENTS OF SUCCESSFUL CLINICAL CANCER RESEARCH NETWORKS WERE IDENTIFIED: shared vision, formal governance policies and terms of reference, infrastructure support, regular and effective communication, an accountability framework, a succession planning strategy to address membership change over time, multiple strategies to engage network members, regular review of goals and timelines, and a balance between structure and creativity. CONCLUSIONS: In establishing and conducting a multi-year, multicentre clinical cancer research network, network members were led to reflect on the factors that contributed most to the achievement of network goals. Several specific factors were identified that seemed to be highly relevant in promoting success. These observations are presented to foster further discussion on the successful design and operation of research networks.

Guidelines for the pharmacological treatment of peripheral neuropathic pain: expert panel recommendations for the middle East region.

Neuropathic pain (NeP) has been the focus of extensive basic and clinical research over the past 20 years. This has led to an increased understanding of underlying pathophysiological mechanisms and the development of new therapeutic agents, as well as a clearer definition of the role of established medications. To date there are no published treatment guidelines for NeP in the Middle East. A multidisciplinary panel of Middle East and international experts met to review critically and reach a consensus on how best to apply evidence-based guidelines for the treatment of NeP (mainly peripheral NeP) in the Middle East. The expert panel recommended pregabalin, gabapentin and secondary amine tricyclic antidepressants (nortriptyline and desipramine) as first-line treatments for peripheral NeP. Serotonin-norepinephrine reuptake inhibitor antidepressants, tramadol and controlled-release opioid analgesics were recommended as second-line treatments. There is a need to increase diagnostic awareness of NeP, use validated screening questionnaires and undertake more treatment research in the Middle East region.

A survey of prelicensure pain curricula in health science faculties in Canadian universities.

OBJECTIVE: The present exploratory, descriptive study aimed to determine the designated time for mandatory pain content in curricula of major Canadian universities for students in health science and veterinary programs before being licensed. METHOD: Major Canadian university sites (n=10) were chosen where health science faculties included at least medicine (n=10) and nursing (n=10); many also included dentistry (n=8), pharmacy (n=7), physical therapy (n=8) and/or occupational therapy (n=6). These disciplines provide the largest number of students entering the workforce but are not the only ones contributing to the health professional team. Veterinary programs (n=4) were also surveyed as a comparison. The Pain Education Survey, developed from previous research and piloted, was used to determine total mandatory pain hours. RESULTS: The majority of health science programs (67.5%) were unable to specify designated hours for pain. Only 32.5% respondents could identify specific hours allotted for pain course content and/or additional clinical conferences. The average total time per discipline across all years varied from 13 h to 41 h (range 0 h to 109 h). All veterinary respondents identified mandatory designated pain content time (mean 87 h, range 27 h to 200 h). The proportion allotted to the eight content categories varied, but time was least for pain misbeliefs, assessment and monitoring/follow-up planning. CONCLUSIONS: Only one-third of the present sample could identify time designated for teaching mandatory pain content. Two-thirds reported 'integrated' content that was not quantifiable or able to be determined, which may suggest it is not a priority at that site. Many expressed a need for pain-related curriculum resources.

Effects of a semiochemical on feed conversion index and related indicators on fast-growing broilers housed during forty-two days.

Consequences of stress in poultry may be assessed through a wide range of parameters. A semiochemical named mother hen uropygial secretion analogue (MHUSA) is known to decrease stress in broilers. Because stress influences their feeding behavior, this trial has been built so as to test the influence of MHUSA on feed conversion index and related indicators. Two hundred forty chicks were placed into 24 similar crates (10 chicks per crate) at 1 d of age. After 35 d, chickens under MHUSA presented similar feed conversion index compared with control. A treatment effect was observed on both heterophil:lymphocyte ratio and corticosterone (MHUSA

Evidence for species differences in the regulation of MMPs by all-trans retinoic acid in cytokine-stimulated chondrocytes.

In inflammatory conditions, chondrocytes produce large amounts of matrix metalloproteases (MMP) and nitric oxide (NO) thought to contribute to joint degradation. We tested the ability of all-trans retinoic acid (ATRA, a retinoic acid receptor (RAR) agonist) to modulate these inflammatory genes in chondrocytes from humans or rats, chosen as representative of animal models of arthritis. All RAR subtypes and RXR-alpha or -beta were expressed at the mRNA level in both species, although IL-1beta (10 ng/ml) inhibited RAR subtypes more markedly in rat than in human cells. ATRA (300 or 1000 nM) inhibited IL-1-induced expression of iNOS and nitrites level in both species, although the NO pathway was induced maximally in rat cells. ATRA displayed controversial effects on MMPs between rat and human chondrocytes, especially for MMP-9 expression. The effects of ATRA were irrelevant to the nuclear translocation of AP-1. The present data underlines that retinoids have a species-dependent impact on IL-1-induced responses in chondrocytes, suggesting that extrapolation of their pharmacological properties from animal cells has a poor relevance to clinical situation.

Conversion from standard opioid therapy to once-daily oral extended-release hydromorphone in patients with chronic cancer pain.

This open-label, multicenter study assessed the efficacy and tolerability of conversion to once-daily OROS hydromorphone from previous opioid agonist therapy in patients with chronic cancer pain. Patients were stabilized on their previous therapy before conversion at a 5:1 ratio of morphine sulfate to hydromorphone hydrochloride. The OROS hydromorphone dose was titrated over 3 - 21 days to achieve effective analgesia and was maintained for up to 14 days. Efficacy was assessed using the Brief Pain Inventory (BPI). Adverse events and vital signs were monitored. Dose stabilization was achieved in 119 of the 127 (94%) patients who received the study medication; in 77%, stabilization was achieved with no titration steps. Mean BPI pain intensity ratings and BPI pain interference scores decreased significantly after OROS hydromorphone treatment compared with pretreatment values. Mean pain-relief level remained stable after conversion and throughout treatment with OROS hydromorphone. Adverse events were as expected for cancer patients receiving opioid agonists. There were no clinically significant changes in vital signs.

Once-daily OROS hydromorphone for the management of chronic nonmalignant pain: a dose-conversion and titration study.

BACKGROUND: The use of opioid analgesics for patients with chronic nonmalignant pain is becoming more widely accepted, and long-acting formulations are an important treatment option. AIM: To assess conversion to extended-release OROS hydromorphone from previous stable opioid agonist therapy in patients with chronic nonmalignant pain of moderate-to-severe intensity. METHODS: In this open-label multicentre trial, patients were stabilised on their previous opioid therapy before being switched to OROS hydromorphone at a ratio of 5 : 1 (morphine sulphate equivalent to hydromorphone hydrochloride). The OROS hydromorphone dose was titrated over 3-16 days to achieve effective analgesia, and maintenance treatment continued for 14 days. RESULTS: Study medication was received by 336 patients; 66% completed all study phases. Stabilisation of OROS hydromorphone was achieved by 94.6% of patients, the majority in two or fewer titration steps (mean time, 4.2 days). Mean pain intensity scores, as determined by the Brief Pain Inventory, decreased during OROS hydromorphone treatment (p

Pharmacological management of chronic neuropathic pain - consensus statement and guidelines from the Canadian Pain Society.

Neuropathic pain (NeP), generated by disorders of the peripheral and central nervous system, can be particularly severe and disabling. Prevalence estimates indicate that 2% to 3% of the population in the developed world suffer from NeP, which suggests that up to one million Canadians have this disabling condition. Evidence-based guidelines for the pharmacological management of NeP are therefore urgently needed. Randomized, controlled trials, systematic reviews and existing guidelines focusing on the pharmacological management of NeP were evaluated at a consensus meeting. Medications are recommended in the guidelines if their analgesic efficacy was supported by at least one methodologically sound, randomized, controlled trial showing significant benefit relative to placebo or another relevant control group. Recommendations for treatment are based on degree of evidence of analgesic efficacy, safety, ease of use and cost-effectiveness. Analgesic agents recommended for first-line treatments are certain antidepressants (tricyclics) and anticonvulsants (gabapentin and pregabalin). Second-line treatments recommended are serotonin noradrenaline reuptake inhibitors and topical lidocaine. Tramadol and controlled-release opioid analgesics are recommended as third-line treatments for moderate to severe pain. Recommended fourth-line treatments include cannabinoids, methadone and anticonvulsants with lesser evidence of efficacy, such as lamotrigine, topiramate and valproic acid. Treatment must be individualized for each patient based on efficacy, side-effect profile and drug accessibility, including cost. Further studies are required to examine head-to-head comparisons among analgesics, combinations of analgesics, long-term outcomes, and treatment of pediatric and central NeP.

[Medical certificates: law, deontology and practice]. / Des certificats médicaux: loi, déontologie et pratique.

At the start of the 21st century, in a society that gives the impression of switching century every five years because of its never-ending evolution, the general practitioner is confronted every day to more complex situations, including problems encountered at the legal level. These last few years, the legal interrogations relevant to medicine and its progress became considerably more extensive in Belgium, as in many other countries. The medical law and its regulation are the subject of many front titles in the press and of animated political debates. The main issues concern the organ transplantation, the meddling with human genetics, the questions related to the reproduction, euthanasia or the protection of the patient's rights. All these legal problems, without exception, are the subject of a great deal of attention in society and create to many controversies. The growing number of regulations in many fields of medicine, as well as their growing complexity, reinforces the importance of the medical law as a distinct discipline of legal sciences. More and more, the doctors of any qualification are required to guarantee, by adequate certificates, the health, the aptitude, the situation of disease of their patients. The patients can then have certain advantages granted by society. Out of concern for their patients, the experts are sometimes tempted not to be perfectly objective. This attitude can lead to penal or disciplinary sanctions and may undermine the confidence of people who exercise authority to give the requested advantages. The initial mistrust, which led to the system of the certificate, extends to those who were supposed to fully collaborate. How to leave this infernal round that sterilizes, denatures the medical act? While waiting for men of goodwill to consider the system and reform it, it remains with the writers of certificates to avoid the traps lying in their path. The purpose of this work is to propose models of certificate that experts can fill in accordance of the circumstances. It is only a guide and consequently, it sometimes requires an interpretation. This is why each model is described together with its justification and its traps.