Resilient liner vs. clip attachment effect on peri‐implant tissues of bar‐implant‐retained mandibular overdenture: a 1‐year clinical and radiographical study

Purpose: The aim of this study was to compare between the effects of resilient liner and clip attachments of bar‐implant‐retained mandibular overdenture on peri‐implant tissues. Materials and methods: In a randomized‐controlled clinical trial, 30 edentulous male patients (mean age 62.5 years) were equally assigned to two groups. In each patient, two implants were inserted in the canine area of the mandible using a two‐stage surgical protocol. After 3 months, the implants were connected with resilient bars. Mandibular overdentures were retained to the bars with either clips (group I) or silicone‐resilient liners (group II). Peri‐implant tissues were evaluated clinically (with regard to plaque scores, gingival scores and probing depths) and radiographically (with regard to peri‐implant vertical and horizontal alveolar bone changes). Evaluations were performed at the time of overdenture insertion (T0), 6 months (T6) and 12 months (T12) after overdenture insertion. Results: After 12 months of using bar‐implant‐retained mandibular overdenture, the resilient liner attachment had significantly decreased peri‐implant plaque score, gingival score, probing depth, vertical and horizontal bone loss when compared with the clip attachment. Conclusion: Within the limitations of this study, and in terms of peri‐implant tissue health of bar‐implant‐retained mandibular overdenture, we recommend resilient liner rather than clip attachment. To cite this article:
Elsyad MA, EL Shoukouki AH. Resilient liner vs. clip attachment effect on peri‐implant tissues of bar‐implant‐retained mandibular overdenture: a 1‐year clinical and radiographical study.
Clin. Oral Impl. Res. 21 , 2010; 473–480
doi: 10.1111/j.1600‐0501.2009.01879.x     

Gene by stress genome-wide interaction analysis and path analysis identify EBF1 as a cardiovascular and metabolic risk gene

We performed gene–environment interaction genome-wide association analysis (G × E GWAS) to identify SNPs whose effects on metabolic traits are modified by chronic psychosocial stress in the Multi-Ethnic Study of Atherosclerosis (MESA). In Whites, the G × E GWAS for hip circumference identified five SNPs within the Early B-cell Factor 1 (EBF1) gene, all of which were in strong linkage disequilibrium. The gene-by-stress interaction (SNP × STRESS) term P-values were genome-wide significant (Ps=7.14E−09 to 2.33E−08, uncorrected; Ps=1.99E−07 to 5.18E−07, corrected for genomic control). The SNP-only (without interaction) model P-values (Ps=0.011–0.022) were not significant at the conventional genome-wide significance level. Further analysis of related phenotypes identified gene-by-stress interaction effects for waist circumference, body mass index (BMI), fasting glucose, type II diabetes status, and common carotid intimal–medial thickness (CCIMT), supporting a proposed model of gene-by-stress interaction that connects cardiovascular disease (CVD) risk factor endophenotypes such as central obesity and increased blood glucose or diabetes to CVD itself. Structural equation path analysis suggested that the path from chronic psychosocial stress to CCIMT via hip circumference and fasting glucose was larger (estimate=0.26, P=0.033, 95% CI=0.02–0.49) in the EBF1 rs4704963 CT/CC genotypes group than the same path in the TT group (estimate=0.004, P=0.34, 95% CI=−0.004–0.012). We replicated the association of the EBF1 SNPs and hip circumference in the Framingham Offspring Cohort (gene-by-stress term P-values=0.007–0.012) as well as identified similar path relationships. This observed and replicated interaction between psychosocial stress and variation in the EBF1 gene may provide a biological hypothesis for the complex relationship between psychosocial stress, central obesity, diabetes, and cardiovascular disease.     

Further delineation of the KBG syndrome caused by ANKRD11 aberrations

Loss-of-function variants in ANKRD11 were identified as the cause of KBG syndrome, an autosomal dominant syndrome with specific dental, neurobehavioural, craniofacial and skeletal anomalies. We present the largest cohort of KBG syndrome cases confirmed by ANKRD11 variants reported so far, consisting of 20 patients from 13 families. Sixteen patients were molecularly diagnosed by Sanger sequencing of ANKRD11, one familial case and three sporadic patients were diagnosed through whole-exome sequencing and one patient was identified through genomewide array analysis. All patients were evaluated by a clinical geneticist. Detailed orofacial phenotyping, including orthodontic evaluation, intra-oral photographs and orthopantomograms, was performed in 10 patients and revealed besides the hallmark feature of macrodontia of central upper incisors, several additional dental anomalies as oligodontia, talon cusps and macrodontia of other teeth. Three-dimensional (3D) stereophotogrammetry was performed in 14 patients and 3D analysis of patients compared with controls showed consistent facial dysmorphisms comprising a bulbous nasal tip, upturned nose with a broad base and a round or triangular face. Many patients exhibited neurobehavioural problems, such as autism spectrum disorder or hyperactivity. One-third of patients presented with (conductive) hearing loss. Congenital heart defects, velopharyngeal insufficiency and hip anomalies were less frequent. On the basis of our observations, we recommend cardiac assessment in children and regular hearing tests in all individuals with a molecular diagnosis of KBG syndrome. As ANKRD11 is a relatively common gene in which sequence variants have been identified in individuals with neurodevelopmental disorders, it seems an important contributor to the aetiology of both sporadic and familial cases.     

Thiocarbohydrazide-crosslinked chitosan as a bioinspired corrosion inhibitor for protection of stainless steel in 3.5% NaCl

A facile single-step synthesis was performed to cross-link chitosan with thiocarbohydrazide to yield thiocarbohydrazide-chitosan (TC-Cht) which was for the first time evaluated as an inhibitor for corrosion of stainless steel in 3.5% NaCl solution. A comprehensive electrochemical analysis employing electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and cyclic voltammetry (CV) was undertaken and showed that the TC-Cht acts by adsorption on the steel surface and exhibits mixed type behavior with predominantly cathodic nature. The adsorption of TC-Cht molecules on the surface of stainless steel followed the Langmuir isotherm. The TC-Cht showed a high inhibition efficiency of >94% at 500 mg L^?1 concentration. Surface investigation using SEM and EDX supported the inhibitor adsorption on the steel surface.     

The physiological stress response to high-intensity sprint exercise following the ingestion of sodium bicarbonate

The purpose of this study was to investigate the effects of pre-exercise alkalosis on the physiological stress response to high-intensity exercise. Seven physically active males (age 22 ± 3 years, height 1.82 ± 0.06 m, mass 81.3 ± 8.4 kg and peak power output 300 ± 22 W) performed a repeated sprint cycle exercise following a dose of 0.3 g kg^?1 body mass of sodium bicarbonate (NaHCO₃) (BICARB), or a placebo of 0.045 g kg^?1 body mass of sodium chloride (PLAC). Monocyte-expressed heat shock protein 72 (HSP72) and plasma thiobarbituric acid reactive substances (TBARS) were significantly attenuated in BICARB compared to PLAC (p = 0.04 and p = 0.039, respectively), however total anti-oxidant capacity, the ratio of oxidised to total glutathione, cortisol, interleukin 6 and interleukin 8 were not significantly induced by the exercise. In conclusion, monocyte-expressed HSP72 is significantly increased following high-intensity anaerobic exercise, and its attenuation following such exercise with the ingestion of NaHCO₃ is unlikely to be due to a decreased oxidative stress.     

The “ways” we look at dreams: evidence from unilateral spatial neglect (with an evolutionary account of dream bizarreness)

Despite decades of research, the question of whether the rapid eye movements (REMs) of paradoxical sleep (PS) are equivalent to waking saccades and whether their direction is congruent with visual spatial events in the dream scene is still very controversial. We gained an insight into these questions through the study of a right brain damaged patient suffering attentional neglect for the left side of space and drop of the optokinetic nystagmus (OKN) with alternating rightward slow/leftward fast phases evoked by rightward optic flow. During PS the patient had frequent Nystagmoid REMs with alternating leftward slow/rightward fast phases and reported dreams with visual events evoking corresponding OKN such as a train running leftward. By contrast, just as in waking OKN, Nystagmoid REMs with alternating rightward slow/leftward fast phases were virtually absent. REMs followed by staring eye position or by consecutive REMs were also observed: these showed no asymmetry comparable to that of Nystagmoid ones. The selective disappearance of Nystagmoid REMs in one horizontal direction proves, for the first time, that in humans different types of REMs exists and that these are driven by different premotor mechanisms. Concomitant drop of OKN and Nystagmoid REMs toward the same horizontal direction demonstrates that phylogenetically ancient oculomotor mechanisms, such as the OKN, are shared by waking and PS. On this evidence and converging findings from animal, neuropsychological and brain imaging studies, a new evolutionary account of dream bizarreness is proposed. Classification and labelling of the different types of REMs are also provided.