Accurate classification of childhood brain tumours by in vivo 1H MRS – A multi-centre study

AimsTo evaluate the accuracy of single-voxel Magnetic Resonance Spectroscopy (¹H MRS) as a non-invasive diagnostic aid for paediatric brain tumours in a multi-national study. Our hypotheses are (1) that automated classification based on ¹H MRS provides an accurate non-invasive diagnosis in multi-centre datasets and (2) using a protocol which increases the metabolite information improves the diagnostic accuracy.MethodsSeventy-eight patients under 16 years old with histologically proven brain tumours from 10 international centres were investigated. Discrimination of 29 medulloblastomas, 11 ependymomas and 38 pilocytic astrocytomas (PILOAs) was evaluated. Single-voxel MRS was undertaken prior to diagnosis (1.5 T Point-Resolved Spectroscopy (PRESS), Proton Brain Exam (PROBE) or Stimulated Echo Acquisition Mode (STEAM), echo time (TE) 20–32 ms and 135–136 ms). MRS data were processed using two strategies, determination of metabolite concentrations using TARQUIN software and automatic feature extraction with Peak Integration (PI). Linear Discriminant Analysis (LDA) was applied to this data to produce diagnostic classifiers. An evaluation of the diagnostic accuracy was performed based on resampling to measure the Balanced Accuracy Rate (BAR).ResultsThe accuracy of the diagnostic classifiers for discriminating the three tumour types was found to be high (BAR 0.98) when a combination of TE was used. The combination of both TEs significantly improved the classification performance (p < 0.01, Tukey’s test) compared with the use of one TE alone. Other tumour types were classified accurately as glial or primitive neuroectodermal (BAR 1.00).Conclusion¹H MRS has excellent accuracy for the non-invasive diagnosis of common childhood brain tumours particularly if the metabolite information is maximised and should become part of routine clinical assessment for these children.     

Morphological study of root surfaces in teeth with adult periodontitis

BACKGROUND: Our study correlates the histological alterations in the cementum (especially resorption areas) of teeth with the different stages of adult periodontitis. METHODS: Sixty-seven teeth affected by adult periodontitis and 7 healthy teeth extracted from patients over 40 years old were used. The teeth were divided into 3 groups according to radiographic data: group 1: five teeth with bone loss less than one-third of the normal alveolar height; group 2: thirty-one teeth with bone loss between one and two thirds; and group 3: thirty-one teeth with bone loss greater than two thirds. The samples were prepared for light and scanning electron microscopy, considering the gingival, middle, and apical thirds in each root. RESULTS: Two control teeth, 4 teeth in group 1, and all teeth in groups 2 and 3 showed resorption areas. Regarding the gingival third, the control teeth did not show any resorption, while 25% of affected teeth in group 1, 38.7% of teeth in group 2, and 35.5% of teeth in group 3 exhibited resorption. Regarding the middle third, 50% of affected teeth belonging to the control group and group 1; 67.7% of teeth in group 2; and 87.1% of teeth in group 3 showed resorption. Regarding the apical third, all teeth belonging to the control group and group 1 showed resorption, while 93.5% and 87.1% of teeth in groups 2 and 3, respectively, exhibited resorption. Most of the resorptions did not extend beyond the cementum. However, in 29.0% of teeth in group 2 and 38.7% of teeth in group 3, resorption had spread as far as the dentin. All the lesions in the control group and group 1 were practically repaired, while only 71.0% of teeth in group 2 and 61.3% of teeth in group 3 showed some sign of reparation. However, in groups 2 and 3, practically all lesions affecting dentin were repaired. CONCLUSIONS: These data suggest that the spread of root resorption is associated with inflammation. This study also suggests that the capacity for repair of root resorption is diminished with greater severity of periodontitis.     

Novel use of cranial epidural space in rabbits as an animal model to investigate bone volume augmentation potential of different bone graft substitutes

Background

The success of bone augmentation to a major degree depends on the biomechanics and biological conditions of the surrounding tissues. Therefore, an animal model is needed providing anatomical sites with similar mechanical pressures for comparing its influence on different biomaterials for bone regeneration. The present report describes the new bone formation associated to biomaterial in a bursa created in the epidural space, between dura mater and cranial calvaria, under the constant pressure of cerebrospinal fluid.

Methods

Five adult California rabbits were used for the trial. In each animal, two bursae were created in the epidural spaces, in the anterior part of the skull, below both sides of the interfrontal suture. The spaces between dura mater and cranial calvaria were filled with in-situ hardening biphasic calcium phosphate containing hydroxyapatite and beta tricalcium-phosphate (BCP), in-situ hardening phase-pure beta-tricalcium phosphate (β-TCP) or without any biomaterials (sham). After 90 days, the animals were sacrificed, and the defect sites were extracted and processed for histomorphometric analysis by optical and backscattered electron microscopy.

Results

The cranial epidural spaces created (n?=?10) could be preserved by the application both BCP (n?=?3) and β-TCP biomaterials (n?=?3) in all experimental sites. The sites augmented with BCP showed less new bone formation but a trend to better volume preservation than the sites augmented with β-TCP. However, the bone in the BCP sites seemed to be more mature as indicated by the higher percentage of lamellar bone in the sites. In contrast, the created space could not be preserved, and new bone formation was scarce in the sham-operated sites (n?=?4).

Conclusion

The experimental bursae created bilaterally in the epidural space allows comparing objectively bone formation in relation to biomaterials for bone regeneration under permanent physiological forces from cerebrospinal fluid pressure.

     

Influence of additional active ingredients on the effectiveness of non-alcoholic chlorhexidine mouthwashes: a randomized controlled trial

BACKGROUND: Non-alcoholic chlorhexidine mouthwashes are equally effective and have fewer potential risks than hydroalcoholic solutions. Nowadays, other active ingredients are added to these mouthwashes in an attempt to improve their effectiveness and reduce side effects. Following an experimental gingivitis model, this study examined three non-alcoholic commercial mouthwashes having 0.12% chlorhexidine digluconate (CHX) in common. METHODS: Using a double masked, cross-over design, 30 subjects underwent three consecutive experimental phases with three mouthwashes: CHX, CHX + 0.05% sodium fluoride (CHXNaF), and CHX + 0.05% cetylpyridinium chloride (CHX-CPC). In each one of these 21-day phases, the subjects discontinued all oral hygiene measures and were treated exclusively with the experimental mouthwash randomly assigned (an oral rinse twice a day). Each experimental phase was preceded by a 14-day washout period. Levels of gingivitis, dental plaque, supragingival calculus, and dental staining were assessed at baseline and end (day 21) of experimental phases. RESULTS: The evolution of gingival and dental staining indices did not show statistically significant differences between the treatments. Differences were noticed in the plaque index (P = 0.0002), with CHX-NaF the treatment with the greatest increase. Differences were also observed in the supragingival calculus index (P = 0.0136), with CHX-CPC showing a smaller increase. Tongue staining was more frequent with CHX-CPC (P = 0.0141). CONCLUSION: In non-alcoholic 0.12% chlorhexidine mouthwashes, the addition of other active ingredients does not produce beneficial effects, but may even reduce the antiplaque effectiveness or increase tongue staining.     

Clinical and histopathological improvement of psoriasis with oral chondroitin sulfate: a serendipitous finding

We describe the clinical and histopathological results of plaque psoriasis in eleven adult patients with knee osteoarthritis and long-standing, moderate to severe psoriasis resistant to conventional therapy treated with chondroitin sulfate. Patients received 800 mg per day of chondroitin sulfate for 2 months. Skin biopsies were obtained before and after treatment. All patients but one presented a dramatic improvement of the condition of the skin, with a reduction of swelling, redness, flaking, and itching (clearance of psoriasis in one patient), increase in the hydration and softening of the skin, and amelioration of scaling. Histopathologically, there was a statistically significant decrease in epidermal thickness, a decrease in the thickness between the stratum basale and the stratum granulosum, a significant improvement of the degree of psoriasis activity, and a decrease in the number of keratinocytes stained with Ki-67. The confirmation of these serendipitous findings in controlled prospective studies could represent an important advance in the therapeutic armamentarium for patients with psoriasis given the excellent safety profile of chondroitin sulfate.     

Use of Biotechnological Devices in the Quantification of Psychophysiological Workload of Professional Chess Players

Psychophysiological requirements of chess players are poorly understood, and periodization of training is often made without any empirical basis. For this reason, the aim of the present study was to investigate the psychophysiological response and quantify the player internal load during, and after playing a chess game. The participant was an elite 33 year-old male chess player ranked among the 300 best chess players in the world. Thus, cortical arousal by critical flicker fusion threshold, electroencephalogram by the theta Fz/alpha Pz ratio and autonomic modulation by heart rate variability were analyzed. Data revealed that cortical arousal by critical flicker fusion threshold and theta Fz/alpha Pz ratio increased and heart rate variability decreased during chess game. All these changes indicated that internal load increased during the chess game. In addition, pre-activation was detected in pre-game measure, suggesting that the prefrontal cortex might be preparatory activated. For these reasons, electroencephalogram, critical flicker fusion threshold and heart rate variability analysis may be highly applicable tools to control and monitor workload in chess player.     

Genetic variations of the apolipoprotein E gene determine the plasma triglyceride levels after heart transplantation.

OBJECTIVES: To study whether the presence of the polymorphism in the apolipoprotein E (apo E) gene influences the lipid profile in heart-transplant recipients. METHODS: A cohort of 103 recipients of heart transplant (93 men and 10 women, with a mean age of 47 +/- 13 years) under triple immunosuppressive therapy were submitted to a genetic study of the apo E gene region. Anthropometric and analytical data, including lipid profile and arterial blood pressure were collected prior to transplantation and 3, 6, 12, and 24 months after it. RESULTS: 65 subjects present the genotype E3E3, 27 the genotype E3E4, 6 the genotype E2E3, and 5 the genotype E2E4. Carriers of the E2 allele (that is, genotypes E3E2 and E4E2) had higher total plasma triglyceride (TG) levels after 3 months (3.47 +/- 1.88 mmol/liter p < 0.001) and after 1 year of transplantation (3.13 +/- 1.77 mmol/liter p < 0.05) than the other genotypes. There were no differences in the plasma levels of total cholesterol (TC), LDL-cholesterol (LDL-C), and HDL-cholesterol (HDL-C). Multiple regression analysis revealed that the apoprotein E gene polymorphism determines 5% (p = 0.0425) and age 8.7% (p < 0.009) of the variants in TG levels. CONCLUSIONS: The presence of the E2 allele in heart-transplant recipients produces a greater rise in total TG plasma levels than the other genotypes.