Single-Implant Overdentures Retained by a Novel Attachment: A Mixed Methods Crossover Randomized Clinical Trial.

INTRODUCTION: Single-implant mandibular overdentures (SIMOs) are one of the least invasive implant treatments for edentulism. The new Novaloc attachment system can improve the clinical performance of implant-retained overdentures but has not been tested for SIMOs. OBJECTIVES: To compare Novaloc and a gold standard system (Locator) for SIMOs in an edentate elderly population in terms of patient-reported outcomes and device- and treatment-related complications. METHODS: In this single-center crossover randomized clinical trial (RCT), 10 edentulous participants received an implant in the lower midline and had their lower complete dentures converted to SIMOs. The participants received each attachment system for 3 mo in a randomized order, followed by measurement of patient satisfaction and oral health-related quality of life via the McGill Denture Satisfaction Questionnaire and the Oral Health Impact Profile for Edentulous People questionnaire, respectively. Complications were registered throughout the RCT. Patients were interviewed for their experiences with SIMOs and preference for one of the attachment systems. Quantitative analysis employed mixed linear models and chi-square tests (α = 0.05), whereas interview data underwent thematic analysis and, in turn, integration into quantitative data (mixed methods explanatory design). RESULTS: All 10 randomized participants completed the trial. Mean ± SD general satisfaction was 92% ± 8% with Novaloc versus 85% ± 13% with Locator (mean difference, 9%; 95% CI, 1% to 17%). For specific McGill Denture Satisfaction Questionnaire items, only denture stability was significantly increased for Novaloc. Seven participants preferred Novaloc over Locator at the end of the RCT (chi-square, P = 0.045). No difference was found between the attachments in terms of oral health-related quality of life based on the Oral Health Impact Profile for Edentulous People and complications. Thematic analysis revealed high patient satisfaction with SIMOs, with denture stability the main criterion for their satisfaction and attachment preference. CONCLUSION: Among elderly edentulous patients wearing SIMOs, Novaloc led to increased patient satisfaction and preference. Better patient-perceived denture stability may explain this result. The attachment systems exhibited similar short-term maintenance needs. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03126942 (first registered on April 13, 2017). Secondary identifiers: A03-M07-17A (McGill University, Institutional Review Board) and 2018-3873 (McGill University Health Centre, Research Ethics Board). KNOWLEDGE TRANSFER STATEMENT: The results of this mixed methods study can be used by clinicians when choosing which attachment system to use for SIMOs. Results suggest that edentulous patients prefer attachments with a better-defined seating position, such as that of the Novaloc system, as opposed to the nylon matrix on metallic abutment of the Locator system.

HLA and disease associations in Iraq.

The HLA system is deeply involved in susceptibility to a variety of diseases. Relationships between HLA and diseases are of considerable interest and importance, as they provide new tools for studying the inheritance, classification, and pathogenesis of these diseases. Studies on the distribution of HLA antigens in different populations have revealed the existence of racial variation and are therefore a prerequisite for studying HLA and disease associations in different racial groups. This study reviews six articles concerning HLA and disease in the Iraqi population. A comparison of these associations and an analysis of overall antigen frequencies among other Arab population and different ethnic groups are included. Some of our HLA-disease associations confirm other studies reported in these racial groups, while other diseases showed different HLA antigen associations from those recorded in other racial groups.

HLA antigens associated with susceptibility to herpes simplex virus infection.

HLA antigen frequencies in 150 patients with recurrent herpes simplex virus infection and 176 normal Iraqi controls were studied. Highly significant increased frequencies of HLA-A1, -B5 and -DR1 were found in patients as compared to control individuals. The frequencies of HLA-A3 and -A23 were also significantly increased in patients. When we subdivide the patients into groups according to rate of recurrence of symptomatic infection or ELISA reading of antibody titre no preferential association of HLA antigens with any particular subgroup is apparent. These results were compared with published findings for other ethnic populations and found to be compatible with them.

Association of HLA antigens with diabetes mellitus in an Iraqi population.

HLA antigen frequencies in 50 patients with IDDM, 56 patients with NIDDM, and 109 normal Iraqi controls were studied. Three families with one patient suffering from IDDM were also studied. No significant HLA antigens associated with NIDDM were found. Highly significant association of HLA, A1, B8, DR3, and DR4 were found in patients with IDDM as compared to normal individuals. The frequency of HLA-B5 and DR2 were significantly decreased in patients with IDDM. In contrast to previously reported findings in Caucasoids there was no significant association with B15 and a negative association with HLA-B5, not with B7. These results were compared with published findings for Arabs and other ethnic populations.

Experimental haemophilic synovitis: rationale and development of a murine model of human factor VIII deficiency.

Haemophilia is a genetic disease as a result of the deficiency of blood coagulation factor VIII or IX. Bleeding is common, especially into joints where an inflammatory, proliferative synovitis develops resulting in a debilitating arthritis, haemophilic arthropathy. The pathogenesis of blood-induced haemophilic synovitis (HS) is poorly understood. The gross, microscopic and ultrastructural changes that occur in the synovial membrane following human and experimental hemarthrosis have been described. Repeated episodes of bleeding induce synoviocyte hypertrophy and hyperplasia, an intense neovascular response and inflammation of the synovial membrane. The component(s) in blood that initiates these changes is(are) not known, although iron is often proposed as one possibility. Here, we describe a novel murine model of human haemophilia A, which facilitates the examination of large number of animals and tissue specimens. The effects of hemarthrosis on the physical, gross and microscopic changes evoked following joint bleeding are described. Controlled, blunt trauma to the knee joint consistently resulted in joint swelling because of a combination of bleeding and inflammation. Hemosiderin was found in the synovial membrane. Similar to hemarthrosis in human haemophilia, joint bleeding resulted in acute morbidity evidenced by inactivity, weight loss and immobility. With time the animals recovered. The model of experimental murine HS described here has utility in the study of the pathogenesis of HS. This is the first of a series of articles, which will discuss the pathophysiology and characterize the model, with comparison of his model to others which have been published previously. It should provide a useful model to test potential therapeutic interventions.

Transfusion-transmitted virus is not present in factor IX concentrates commonly used to treat haemophilia B.

Transfusion-transmitted virus (TTV) is a potential cause of post-transfusion hepatitis in patients with haemophilia. Plasma-derived clotting factor concentrates currently undergo processes that are effective in removal and inactivation of viruses such as HIV, hepatitis B and C; however, their effectiveness with respect to TTV is unknown. To determine if TTV DNA is present in plasma-derived concentrates of factor IX, we tested 14 lots of Mononine and compared the results with BeneFix. Nucleic acid isolation, followed by a two-round polymerase chain reaction (PCR) and agarose gel analysis indicated that all 17 lots were negative for TTV. Although TTV may be considered an emerging pathogen, no evidence of the virus was detected in the commercially available plasma-derived concentrate of FIX most commonly used to treat haemophilia B.

Atherosclerotic aortic gangliosides enhance integrin-mediated platelet adhesion to collagen.

Gangliosides, sialic acid-containing glycosphingolipids, accumulate in atherosclerotic vessels. Their role in the pathogenesis of atherosclerosis is unknown. Gangliosides isolated from tumor cells promote collagen-stimulated platelet aggregation and ATP secretion and enhance platelet adhesion to immobilized collagen. These activities are all mediated by ganglioside effects on the platelet integrin collagen receptor alpha2beta1. Therefore, we hypothesized that gangliosides isolated from atherosclerotic plaques would enhance platelet adhesion to immobilized collagen, a major component of the subendothelial matrix of blood vessels. Furthermore, we questioned whether this effect of atherosclerotic gangliosides might play a role in the pathogenesis of atherosclerosis. To test this hypothesis, we isolated the gangliosides from postmortem aortas of patients with extensive atherosclerotic disease and examined their effects on platelet adhesion. Samples of aortic tissue taken from areas involved with atherosclerotic plaque demonstrated accumulation of gangliosides (64.9+/-6.5 nmol/g wet weight) compared with gangliosides isolated from control normal aortic tissue taken from children who died of noncardiac causes (NAGs; 21.1+/-6.4 nmol/g wet weight). Interestingly, samples of tissue taken from diseased aortas but from areas not involved with gross plaque formation also demonstrated ganglioside accumulation (47.6+/-12.8 nmol/g wet weight). Next, the activity of each of these gangliosides on platelet adhesion to immobilized type I collagen was studied. Atherosclerotic aortic gangliosides (AAGs) as well as those isolated from grossly unaffected areas of the same aorta (UAGs) both increased platelet adhesion compared with control NAGs (OD570, 0. 37+/-0.11 and 0.29+/-0.14 versus 0.16+/-0.07, respectively; P<0.01 and P<0.05, respectively). These OD570 values corresponded to 9x10(5), 8x10(4), and 6x10(3) platelets per well after preincubation with 5 micromol/L AAG, UAG, and NAG, respectively. Increased adhesion was observed after preincubation with as little as 0.5 micromol/L AAG, and maximal adhesion was seen at 2.5 micromol/L, with a plateau extending to the highest concentration tested, 10 micromol/L. The effect of AAGs on platelet adhesion to collagen was abrogated by incubation of treated platelets with F-17 anti-alpha2 monoclonal antibody (OD570, 0.13+/-0.02). Finally, the effects of the major individual gangliosides isolated from atherosclerotic tissues, GM3 and GD3, were tested. GM3 increased adhesion to collagen (OD570, 0.415+/-0.06) as did GD3 (0.31+/-0.08). Similar to that of AAGs, the effect of both molecules was blocked by F-17 (0. 09+/-0.04 and 0.13+/-0.06, respectively). These experiments demonstrate that accumulated atherosclerotic gangliosides promote platelet adhesion to collagen, the major component of the subendothelial matrix. Furthermore, this activity is mediated by an effect of the gangliosides on the collagen-binding integrin alpha2beta1. This activity may provide a mechanism for the development of platelet thrombi at sites where atherosclerotic gangliosides accumulate and help to explain the role of platelets in the process of atherosclerotic disease progression.

Association of HLA antigens with coeliac disease among Iraqi children.

Forty children with coeliac disease were subjected to HLA-A and B antigens typing using the two-way lymphocytotoxicity technique. An increase in the frequency of HLA-B8 and B12 was found in patients as compared to the control group. Family studies conducted in 4 selected families have indicated that four out of five siblings who inherited the HLA-B8 antigen from their parents have contracted coeliac disease. In one of the families both siblings had HLA-B8 but only one of them contracted coeliac disease. It is suggested that the association of coeliac disease with HLA-antigen could be multifactorial, i.e. the disease could be attributed to the presence of more than one antigen.