Accuracy of cone beam computed tomography in assessing peri-implant bone defect regeneration: a histologically controlled study in dogs

Objective: To assess the accuracy of cone‐beam computed tomography (CBCT) in terms of buccal bone‐wall configuration and peri‐implant bone defect regeneration after guided bone regeneration (GBR). Material and methods: Titanium implants were inserted into standardized box‐shaped defects in the mandible of 12 foxhounds. Defects of one side were augmented following the principle of GBR, while the other side was left untreated. Radiological evaluation was performed using CBCT and compared with histomorphometrical measurements of the respective site serving as a validation method. Results: Non‐augmented control sites providing a horizontal bone width (BW) of<0.5 mm revealed a significantly lower accuracy between the radiological and the histological evaluation of the buccal defect depth (1.93 ± 1.59 mm) compared with the group providing a BW of >0.5 mm (0.7 ± 0.7 mm) (P<0.05, Mann–Whitney U‐test). In GBR‐treated defects, the subgroup <0.5 mm (1.49 ± 1.29 mm) revealed a significantly higher difference between CBCT and histology compared with >0.5 mm (0.82 ± 1.07) (P>0.05, Mann–Whitney U‐test). However, a radiological discrimination between original bone, integrated and non‐integrated bone substitute material was not reliable. Additionally, it was found that a minimum buccal BW of 0.5 mm was necessary for the detection of bone in radiology. Conclusion: The evaluation of peri‐implant bone defect regeneration by means of CBCT is not accurate for sites providing a BW of <0.5 mm. Moreover, a safe assessment of the success of the GBR technique is not possible after the application of a radiopaque bone substitute material. To cite this article:
Fienitz T, Schwarz F, Ritter L, Dreiseidler T, Becker J, Rothamel D. Accuracy of cone beam computed tomography in assessing peri‐implant bone defect regeneration: a histologically controlled study in dogs.
Clin. Oral Impl. Res. 23 , 2012; 882–887.
doi: 10.1111/j.1600‐0501.2011.02232.x     

Calpain inhibition stabilizes the platelet proteome and reactivity in diabetes

Platelets from patients with diabetes are hyperreactive and demonstrate increased adhesiveness, aggregation, degranulation, and thrombus formation, processes that contribute to the accelerated development of vascular disease. Part of the problem seems to be dysregulated platelet Ca(2+) signaling and the activation of calpains, which are Ca(2+)-activated proteases that result in the limited proteolysis of substrate proteins and subsequent alterations in signaling. In the present study, we report that the activation of μ- and m-calpain in patients with type 2 diabetes has profound effects on the platelet proteome and have identified septin-5 and the integrin-linked kinase (ILK) as novel calpain substrates. The calpain-dependent cleavage of septin-5 disturbed its association with syntaxin-4 and promoted the secretion of α-granule contents, including TGF-β and CCL5. Calpain was also released by platelets and cleaved CCL5 to generate a variant with enhanced activity. Calpain activation also disrupted the ILK-PINCH-Parvin complex and altered platelet adhesion and spreading. In diabetic mice, calpain inhibition reversed the effects of diabetes on platelet protein cleavage, decreased circulating CCL5 levels, reduced platelet-leukocyte aggregate formation, and improved platelet function. The results of the present study indicate that diabetes-induced platelet dysfunction is mediated largely by calpain activation and suggest that calpain inhibition may be an effective way of preserving platelet function and eventually decelerating atherothrombosis development.     

Season-dependent symptoms in consultation-liaison patients

INTRODUCTION: We investigated those psychiatric patients whose reason for seeking medical help was primarily a physical condition. Our objectives were to analyse to what extent they suffered from seasonal variation in mood and behaviour during winter, and to examine whether these patients were evenly distributed between the categories of the ICD-10 Classification of Mental and Behavioural Disorders (ICD-10) by their primary diagnosis of mental disorder. METHOD: Patients attending the psychiatric services of a consultation liaison unit were interviewed for diagnosis, and were asked to fill in a questionnaire on seasonal variation in mood and behaviour. RESULTS: Our results suggest that there are many patients fulfilling the criteria based on the Seasonal Pattern Assessment uestionnaire (SPA) for seasonal affective disorder (SAD) or for subsyndromal SAD, not only in the ICD-10 diagnosis category of mood (affective) disorders but also in other disorder categories. CONCLUSION: This observation is of importance to hospital and private clinicians, as it emphasizes the need to assess the clinical picture in detail and to consider treatment alternatives for patients presenting with mental disorder with a seasonal pattern. (Int J Psych Clin Pract 2000; 4:151-154)     

Laser Doppler imaging in the detection of peripheral neuropathy

Small fiber neuropathy is common in a number of systemic diseases and is often challenging to diagnose. Laser Doppler imaging (LDI) is a test of small fiber neurovascular function that can quantify the integrity of the vasomotor C-fiber mediated axon-reflex, but no standardized method of analysis exists. We developed a novel LDI analysis technique and tested it in a human model of small fiber neuropathy. Eighteen healthy subjects (age 24 ± 3 years) underwent LDI testing to assess the axon-mediated flare area in response to 10% acetylcholine iontophoresis. LDI measurements were taken before and longitudinally after a 48-hour application of 0.1% capsaicin (to cause a transient small fiber neuropathy) on the skin of the thigh; placebo cream was placed on the contralateral thigh as a control. We compared our new LDI image analysis technique to two previously published methods. The new LDI analysis technique was the only method to show a consistent difference in axon-reflex area between capsaicin treated and placebo treated skin on all testing days (p < 0.05) with maximum attenuation of the flare area immediately post-application (438 ± 298 mm² vs. 824 ± 375 mm², p < 0.05). In conclusion, this study demonstrates that our novel flare area method for LDI analysis can detect neurovascular dysfunction in a model of small fiber neuropathy, is an improvement over existing methods, and may supplement clinical assessment of small fiber neuropathy.     

Computer-assisted orthognathic surgery: waferless maxillary positioning,versatility, and accuracy of an image-guided visualisation display

There may well be a shift towards 3-dimensional orthognathic surgery when virtual surgical planning can be applied clinically. We present a computer-assisted protocol that uses surgical navigation supplemented by an interactive image-guided visualisation display (IGVD) to transfer virtual maxillary planning precisely. The aim of this study was to analyse its accuracy and versatility in vivo. The protocol consists of maxillofacial imaging, diagnosis, planning of virtual treatment, and intraoperative surgical transfer using an IGV display. The advantage of the interactive IGV display is that the virtually planned maxilla and its real position can be completely superimposed during operation through a video graphics array (VGA) camera, thereby augmenting the surgeon's 3-dimensional perception. Sixteen adult class III patients were treated with by bimaxillary osteotomy. Seven hard tissue variables were chosen to compare (ΔT₁–T₀) the virtual maxillary planning (T₀) with the postoperative result (T₁) using 3-dimensional cephalometry. Clinically acceptable precision for the surgical planning transfer of the maxilla (<0.35 mm) was seen in the anteroposterior and mediolateral angles, and in relation to the skull base (<0.35°), and marginal precision was seen in the orthogonal dimension (<0.64 mm). An interactive IGV display complemented surgical navigation, augmented virtual and real-time reality, and provided a precise technique of waferless stereotactic maxillary positioning, which may offer an alternative approach to the use of arbitrary splints and 2-dimensional orthognathic planning.     

Clustering of Metabolic Risk Factors Is Associated with High-Normal Levels of Liver Enzymes Among 6- to 8-Year-Old Children: The PANIC Study

Abstract Background: We studied the associations of clustering of metabolic risk factors with plasma levels of alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) in healthy prepubertal children. Methods: The subjects were a representative population sample of 492 children 6-8 years of age. We assessed body fat percentage (dual-energy X-ray absorptiometry), body mass index, waist circumference, systolic and diastolic blood pressure, glucose, insulin, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides, ALT, GGT, and high-sensitivity C-reactive protein (hsCRP) and calculated a continuous metabolic syndrome score variable. We also used factor analysis to examine whether high-normal liver enzymes are a feature of metabolic syndrome among children. Results: Children with overweight or obesity, defined by International Obesity Task Force (IOTF) criteria, had a 2.1-times higher risk of having ALT and a 4.5-times higher risk of having GGT in the highest fifth of its distribution than normal weight children. Children in the highest sex-specific third of metabolic syndrome score, body fat percentage, waist circumference, and insulin had a two to three times higher risk of being in the highest fifth of ALT and GGT. Moreover, children in the highest third of glucose and hsCRP had a 2.5-fold risk of being in the highest fifth of GGT. First-order factor analysis yielded three factors; the first included insulin, glucose, and triglycerides; the second waist circumference, insulin, GGT, and hsCRP; and the third HDL-C, triglycerides, waist circumference, and insulin. Second-order factor analysis yielded a single metabolic syndrome factor, explaining 64.1% of the variance. Conclusions: Clustering of metabolic risk factors, particularly excess body fat, is associated with high-normal levels of ALT and GGT in prepubertal children. High-normal levels of liver enzymes, especially GGT, and systemic low-grade inflammation could be considered features of metabolic syndrome among children. Subtle changes in liver function may play an important role in the pathogenesis of metabolic syndrome beginning in childhood.     

Cardiorespiratory fitness is not associated with risk of venous thromboembolism: a cohort study

Abstract

Objectives. The inverse and independent association between cardiorespiratory fitness (CRF) and arterial thrombotic disease is well established. However, the potential association between CRF and venous thromboembolism (VTE) is not well known. We aimed to assess the prospective association of CRF with the risk of VTE. Design. Cardiorespiratory fitness, as measured by maximal oxygen uptake (VO_2max), was assessed using a respiratory gas exchange analyser in 2,249 men aged 42–61 years without a history of VTE at baseline in the Kuopio Ischemic Heart Disease prospective cohort. Cox-regression models were used to calculate hazard ratios (HR) with 95% confidence interval (CI) for VTE. We corrected for within-person variability in CRF levels using data from repeat measurements taken several years apart. Results. There were 144 (6.4%) incident VTE events recorded during a median follow-up of 25.2 years. The age-adjusted regression dilution ratio of CRF was 0.58 (95% CI: 0.53–0.64). The risk of VTE did not significantly decrease per 1 standard deviation increase in CRF in age-adjusted analysis (HR 0.90; 95% CI 0.75–1.08). The association remained consistent in analyses adjusted for several established and emerging risk factors (HR 0.90; 95% CI 0.73–1.12). The corresponding adjusted HRs were 0.80 (95% CI: 0.52–1.23) and 0.82 (95% CI: 0.51–1.32) respectively, when comparing the extreme tertiles of CRF levels. Conclusions. In a middle-aged Caucasian male population, CRF was not associated with future risk of VTE. Further studies are required to confirm and to generalize these findings, particulary in women and other age groups.