Illusory Essences: A Bias Holding Back Theorizing in Psychological Science

The reliance in psychology on verbal definitions means that psychological research is unusually moored to how humans think and communicate about categories. Psychological concepts (e.g., intelligence, attention) are easily assumed to represent objective, definable categories with an underlying essence. Like the “vital forces” previously thought to animate life, these assumed essences can create an illusion of understanding. By synthesizing a wide range of research lines from cognitive, clinical, and biological psychology and neuroscience, we describe a pervasive tendency across psychological science to assume that essences explain phenomena. Labeling a complex phenomenon can appear as theoretical progress before there is sufficient evidence that the described category has a definable essence or known boundary conditions. Category labels can further undermine progress by masking contingent and contextual relationships and obscuring the need to specify mechanisms. Finally, we highlight examples of promising methods that circumvent the lure of essences and suggest four concrete strategies for identifying and avoiding essentialist intuitions in theory development.

HLA typing and haematopoietic stem cell transplantation in the histocompatibility unit of the Ibn Sina University Hospital in Rabat (Morocco)

PURPOSE OF STUDY

This study focuses on the search for a suitable related HLA-matched donor of haematopoietic stem cells in the context of allogeneic transplantation in Morocco. The aim of this work is to establish whether the related donor can meet graft needs in Moroccan patients.

PATIENTS AND METHODS

429 families (429 recipients and 965 donors) benefited from HLA typing, using microlymphocytotoxicity, polymerase chain reaction-sequence specific primer and/or high-resolution polymerase chain reaction-specific sequence oligonucleotide.

RESULTS

The recipients and donors are mostly men over 18 years of age. In total, 86.8% of the recipients have between 1 and 3 donors who are 96% of the collaterals. Malignant haemopathies account for 54% of allograft indications. Benign haemopathies are more frequent than malignant in children, whereas the profile is reversed in adults. Fifty percent of recipients have an HLA identical donor in their siblings and 42% and HLA haplo identical donor. The HLA typing of the recipients and the donors reveals very large polymorphism of the population.

CONCLUSION

The related donor of haematopoietic stem cells represents an important source of grafts but will not be able to satisfy all the needs of Morocco. The creation of national unrelated voluntary donors will open up new possibilities for recipients who do not have a compatible donor within his relatives.

[Immunological monitoring in kidney transplantation: 13 years experience of a Moroccan histocompatibility laboratory]

PURPOSE OF STUDY

The quality of the immunological monitoring is crucial because it determines the success of the kidney transplantation. The scope of this work is to describe the experience of the department of immunological unity of the Ibn Sina university hospital in Rabat regarding the immunological monitoring of patients transplanted between 2001 and 2014.

PATIENTS AND METHODS

Patient samples were collected from nephrology services of different public and private hospitals of Morocco. The tests conducted in the context of immunological monitoring are ABO typing, HLA-A, B, DR, DQ typing, anti-HLA antibodies detection and identification and cross-match.

RESULTS

One hundred and fourteen benefited from a pre- and post-transplant immunological monitoring in our laboratory. The percentage of recipients having between 2 and 5 stored sera is 60.5 before transplantation and 56.1 after transplantation. Immunized patients account for 22.8% before the transplant and 17.6% after transplantation. Ninety-seven patients still have a functional graft, while 4 of them had DSA of low intensity before transplantation. Five immunological rejections were reported while the cross-match were negative and no DSA was identified before transplantation. Patient survival and graft at 1 year was 98.2% and 92.7% respectively.

CONCLUSION

Conducting regular immunological monitoring is sometimes difficult in our context, however, the results are satisfactory in terms of graft and patients survival.

[The HLA system in the Moroccan population: General review]

The Moroccan population is an interesting study model of Human Leukocyte Antigen (HLA) polymorphism given its ethnic and genetic diversity. Through an analysis of the literature, this work proposes to establish a balance of knowledge for this population in the field of histocompatibility: HLA diversity, anthropology, transplantation and HLA associations and diseases. This analysis shows that the HLA system has not been fully explored within the Moroccan population. However, the results obtained allowed us to initiate a database reflecting the specific healthy Moroccan population HLA polymorphism to identify immigration flows and relationships with different people of the world and to reveal the association of certain HLA alleles with frequent pathologies. We also propose to analyze the reasons hindering the development of this activity in Morocco and we will try to identify some perspectives.

[Management by objectives: an experience by transfusion and immunology service in Rabat]

The management by objectives method has become highly used in health management. In this context, the blood transfusion and haemovigilance service has been chosen for a pilot study by the Head Department of the Ibn Sina Hospital in Rabat. This study was conducted from 2009 to 2011, in four steps. The first one consisted in preparing human resources (information and training), identifying the strengths and weaknesses of the service and the identification and classification of the service's users. The second step was the elaboration of the terms of the contract, which helped to determine two main strategic objectives: to strengthen the activities of the service and move towards the "status of reference." Each strategic objective had been declined in operational objectives, then in actions and the means required for the implementation of each action. The third step was the implementation of each action (service, head department) so as to comply with the terms of the contract as well as to meet the deadlines. Based on assessment committees, the last step consisted in the evaluation process. This evaluation was performed using monitoring indicators and showed that management by objectives enabled the Service to reach the "clinical governance level", to optimize its human and financial resources and to reach the level of "national laboratory of reference in histocompatibility". The scope of this paper is to describe the four steps of this pilot study and to explain the usefulness of the management by objectives method in health management.

Distribution of HLA class I and II genes in ankylosing spondylitis patients from Morocco

OBJECTIVES

In Morocco, the patients affected by ankylosing spondylitis (AS) presents a high frequency of coxitis. Our study reports, for the first time, the polymorphism of Human Leukocyte Antigen (HLA) class I and class II molecules in the Moroccan patients.

METHODS

Forty-six patients diagnosed with an AS and coxitis were compared to a group of 183 healthy controls matched by age, sex and ethnic origin. The HLA typing was performed using microlymphocytotoxicity for the class I (-A, -B) and PCR-SSP for the class II (-DR, -DQ).

RESULTS

We found a significant increase of the HLA-B27 antigen frequency (P<0.0001, RR=20.9) in AS patients (29.3%) compared to the controls (3.2%) and a significant decrease in the frequency of HLA-B12 and HLA-B18 antigens. Examination of HLA class II distribution shows a significant increase of the HLA-DRB1*11 allele frequency in patients (P<0.0001). Concerning HLA-DQB1* alleles, no significant difference between patients and controls was appreciable.

CONCLUSIONS

The HLA-B27 antigen is involved in the predisposition to the AS with coxitis in the Moroccan population. However, the low frequency observed in our population suggests the existence of other genetic and/or environmental factors. Other HLA genes seem to confer a predisposing effect (DRB*11) or a protective effect (B12 and B18) against the disease.

[Traceability of labile blood products in Morocco: experience of the Ibn-Sina hospital of Rabat between 1999 and 2010]

PURPOSE OF STUDY

The blood transfusion and haemovigilance service of the Ibn-Sina hospital in Rabat (Morocco) was created 1997. This unit manages the pretransfusional tests, distribution of blood products, traceability and haemovigilance. The objective of this study was to analyze, over a period of 12years, the traceability of blood products delivered in our hospital and the measures used to improve feedback information.

PATIENTS AND METHODS

This is a retrospective study conducted between 1999 and 2010. Traceability rate was calculated from the feedback of traceability forms supplied with blood products (number of blood products noted on traceability forms on the total number of delivered product). To improve traceability rate, several actions were undertaken: one-time training, awareness campaigns and call phones asking for feedback information.

RESULTS

Between 1999 and 2010, the service has delivered 173,858 blood products. The average rate of traceability during this period was 13.4 %. Traceability rate varies widely over time (5.2 % in 1999, 15.5 % in 2010) and shows a maximum value of 27.2 % in 2005. Feedback information is lower in emergency departments than in medical and surgical services.

CONCLUSION

Feedback information about traceability in Ibn-Sina hospital remains very poor despite the measures used. Other actions, such as continuous education courses, low enforcement and informatisation should be considered.

[The latest TH17 lymphocyte in the family of T CD4+ lymphocytes]

In recent years the T CD4+ lymphocyte family has grown. In the initial two components TH1 and TH2 lymphocytes were added the TH17 lymphocyte and T cell regulator (Treg). Under the influence of transforming growth factor β, interleukin 6 (IL6), IL21 and IL23, the naive lymphocyte T CD4+ differentiates in TH17. Currently, the TH17 is recognized as the leading actor of local inflammation through the pro-inflammatory cytokines (interleukins 17, 21, 22) that secretes and the expansion and recruitment of neutrophils that leads. Therefore, it is involved in chronic inflammatory processes, autoimmune diseases (rheumatoid arthritis, systemic lupus erythematosus), allergy and rejection of allogeneic transplants. TH17 lymphocyte opens up new therapeutic prospects for these pathologies.

[Toll-like receptors]

The toll-like receptors are innate immunity receptors which recognise particular exogenous structures in the microorganisms pathogen associated molecular pattern (PAMP) and endogenous structures damage-associated molecular patterns (DAMP). Eleven TLR have been identified among human beings. These are danger receptors located in the cells of the immune system but also in other cells. Their primary function is the recognition of pathogens and the activation of the cell that holds them. It follows from it an action on the cells environment, inflammation cells and an activation of the adaptive immunity. The knowledge of the intracellular signalisation ways of the TLR has allowed us to understand the physiopathology of certain diseases. Thus, several works use the agonists of TLR to stimulate them: vaccines against infectious diseases, allergies and cancers. The antagonists are used to block the TLR in autoimmune and chronic inflammatory diseases. It is clear that the border between innate and adaptive immunity fades and that these two components of the immune response are closely related, thus opening up new prospects diagnostic and therapeutic procedures.

HLA-A, -B, -DR and -DQ allele and haplotype frequencies in the Moroccan population: a general population study

PURPOSE OF STUDY

The aim of this general population study is to extend our knowledge about the HLA-A, -B, -DR and -DQ genes distribution and their diversity among the Moroccan population.

PATIENTS AND METHODS

One hundred and ten unrelated healthy Moroccans from diverse regions of the country were included in the study. HLA typing was done either by serological (standard complement dependent microlymphocytotoxicity) and/or molecular (sequence-specific primer amplification) techniques.

RESULTS

The most frequent alleles observed were: HLA-A2 (19.1%), -A1 (10%), -A3 (10%), -B44 (9.6%), -DR3 (17.1%), -DR4 (15.3%), -DQ2 (30.6%), -DQ6 (26.4%) and -DQ3 (25%). No predominant haplotype was observed for HLA A-B while high frequency was observed for some HLA DR-DQ associations (DR3-DQ2, DR15-DQ6, DR7-DQ2, DR4-DQ3, DR13-DQ6). Comparison with neighbouring populations, on the basis of alleles, haplotypes and genetic distances, showed that Moroccan population is close to the Algerians, the Tunisians, the Spaniards and the French. The haplotype frequencies revealed also relationships with Italians, Sardinians, Basques, Portuguese and Moroccan Jews populations.

CONCLUSION

Our results confirm and extend the current knowledge about the Moroccan genetic pattern and reflect all the ethnic diversity of the country. This study will be helpful in the future for clinical analysis like transplantation and HLA-associated diseases in Moroccan population.

Spinal pedicle fixation: reliability and validity of roentgenogram-based assessment and surgical factors on successful screw placement

The increased popularity of pedicle fixation prompted research to address two issues: the reliability and validity of roentgenograms as a technique for evaluating the success of pedicle fixation, and the effects of surgical factors on successful fixation. Thus, does approach--the point and angle of screw insertion, surgeon experience, practice, level of the spine involved, and screw size--effect success of pedicle fixation? Eight fresh thoracolumbar spines were harvested and cleaned of all soft tissues. Two surgeons, one more experienced in pedicle fixation than the other, used two pedicle fixation approaches (Weinstein and Roy-Camille) on both the left and right sides at levels T11-S1 of each specimen. All screws were placed under anteroposterior (AP) and lateral c-arm control. For specimens 1 to 3, 5.5 mm screws were used at T11-L1, and 7.0 mm screws at L2-S1. Unacceptable failure rates at L2 and L3 for the first three specimens resulted in a change of instrumentation for the remaining specimens, with 5.5 mm screws used at T11-L3 and 7.0 mm screws at L4-S1. When surgeons completed the fixations for a specimen, AP and lateral roentgenograms were taken and both surgeons independently evaluated the films to assess the success of each fixation. Failure was defined as evidence of any cortical perforation on any side of the pedicle in or outside of the spinal canal. After completing the roentgenogram evaluation, the specimen was transected in the midline, and the success of each pedicle fixation was evaluated by visual/tactile inspection. There were no disagreements between surgeons on the visual/tactile evaluations of the specimens.(ABSTRACT TRUNCATED AT 250 WORDS)