Influence of host-related risk indicators on dental caries in permanent dentition

The aim of this study was to assess the individual and grouped influence of host-related factors on dental caries experience in permanent dentition of 7-9 year-old children. One hundred and twenty one children were recruited applying a stratified cluster sampling without replacement. Clinical examinations, Colorimetric Test and non-stimulated and stimulated saliva collection were performed; the samples obtained were later incubated using Snyder culture medium. Simple and multiple binary logistic regression analyses were performed to assess the individual and grouped influence of the host-related factors and establish a modelfor predicting dental caries in permanent dentition. 78.5% of the evaluated children presented dental caries in permanent dentition. Binary logistic regression analyses revealMd that only dental caries in deciduous dentition and stimulated salivary flow were significantly associated to dental caries in permanent dentition. The final multivariate model showed that the adjusted OR was 1.76 for an increase of 1 tooth in dmft and 2.29 for a decrease of 1 ml in stimulated salivary flow. Dental caries in deciduous dentition is a risk indicator for dental caries in permanent dentition, and stimulated salivary flow is a protective factor Variables like enamel resistance to acid dissolution and buffer capacity are not related to dental caries in permanent dentition, making them inappropriate for risk studies.     

POMT2 mutations cause alpha-dystroglycan hypoglycosylation and Walker-Warburg syndrome

Background: Walker-Warburg syndrome (WWS) is an autosomal recessive condition characterised by congenital muscular dystrophy, structural brain defects, and eye malformations. Typical brain abnormalities are hydrocephalus, lissencephaly, agenesis of the corpus callosum, fusion of the hemispheres, cerebellar hypoplasia, and neuronal overmigration, which causes a cobblestone cortex. Ocular abnormalities include cataract, microphthalmia, buphthalmos, and Peters anomaly. WWS patients show defective O-glycosylation of α-dystroglycan (α-DG), which plays a key role in bridging the cytoskeleton of muscle and CNS cells with extracellular matrix proteins, important for muscle integrity and neuronal migration. In 20% of the WWS patients, hypoglycosylation results from mutations in either the protein O-mannosyltransferase 1 (POMT1), fukutin, or fukutin related protein (FKRP) genes. The other genes for this highly heterogeneous disorder remain to be identified. Objective: To look for mutations in POMT2 as a cause of WWS, as both POMT1 and POMT2 are required to achieve protein O-mannosyltransferase activity. Methods: A candidate gene approach combined with homozygosity mapping. Results: Homozygosity was found for the POMT2 locus at 14q24.3 in four of 11 consanguineous WWS families. Homozygous POMT2 mutations were present in two of these families as well as in one patient from another cohort of six WWS families. Immunohistochemistry in muscle showed severely reduced levels of glycosylated α-DG, which is consistent with the postulated role for POMT2 in the O-mannosylation pathway. Conclusions: A fourth causative gene for WWS was uncovered. These genes account for approximately one third of the WWS cases. Several more genes are anticipated, which are likely to play a role in glycosylation of α-DG.     

Structure activity relationship, acute toxicity and cytotoxicity of antimycobacterial neolignan analogues

Objectives The study's aims were to evaluate the antimycobacterial activity of 13 synthetic neolignan analogues and to perform structure activity relationship analysis (SAR). The cytotoxicity of the compound 2‐phenoxy‐1‐phenylethanone (LS‐2, 1 ) in mammalian cells, such as the acute toxicity in mice, was also evaluated. Methods The extra and intracellular antimycobacterial activity was evaluated on Mycobacterium tuberculosis H37Rv. Cytotoxicity studies were performed using V79 cells, J774 macrophages and rat hepatocytes. Additionally, the in‐vivo acute toxicity was tested in mice. The SAR analysis was performed by Principal Component Analysis (PCA). Key findings Among the 13 analogues tested, LS‐2 ( 1 ) was the most effective, showing promising antimycobacterial activity and very low cytotoxicity in V79 cells and in J774 macrophages, while no toxicity was observed in rat hepatocytes. The selectivity index (SI) of LS‐2 ( 1 ) was 91 and the calculated LD50 was 1870 mg/kg, highlighting the very low toxicity in mice. SAR analysis showed that the highest electrophilicity and the lowest molar volume are physical‐chemical characteristics important for the antimycobacterial activity of the LS‐2 ( 1 ). Conclusions LS‐2 ( 1 ) showed promising antimycobacterial activity and very weak cytotoxicity in cell culture, as well as an absence of toxicity in primary culture of hepatocytes. In the acute toxicity study there was an indication of absence of toxicity on murine models, in vivo.     

Polymer Nanocomposites Containing Anisotropic Metal Nanostructures as Internal Strain Indicators

Polymer/metal nanocomposite containing intrinsically anisotropic metal nanostructures such as metal nanorods and nanowires appeared extremely more sensitive and responsive to mechanical stimuli than nanocomposites containing spherical nanoparticles. After uniaxial stretching of the supporting polymer matrix (poly(vinyl alcohol)), the elongated silver nanostructures embedded at low concentration into the polymer matrix (<1 wt % of Ag) assume the direction of the drawing, yielding materials with a strong dichroic response of the absorption behavior. Accordingly, the film changed its color when observed under linearly polarized light already at moderate drawings. The results obtained suggest that nanocomposite films have potential in applications such as color polarizing filters, radiation responsive polymeric objects and smart flexible films in packaging applications.     

Transbronchial Lung Biopsy Using Cryoprobes

Background and objectivesTransbronchial lung biopsy (TBLB) is a bronchoscopy procedure used to obtain peripheral lung tissue. Small size samples and artefacts lead to variable, and usually poor, diagnostic yield. The use of cryoprobes may enable larger size and better quality biopsy samples to be obtained. The purpose of this study was to evaluate the feasibility of TBLB with cryoprobes and analyse the histological quality of samples obtained.Patients and methodsWe selected 10 patients with interstitial lung disease who were suitable for TBLB. A cryoprobe (Erbokryo CA^®, Erbe, Germany) was introduced through the bronchoscope work channel. Then, under fluoroscopic control, the cryoprobe was placed in an area of the peripheral lung previously selected according to CT findings. A temperature of ?89.5° C was applied for 3s and the cryoprobe and bronchoscope were removed with the frozen lung sample attached to the probe. The procedure was performed under sedation and the patient was intubated to allow bronchoscope and cryoprobe removal. Safety, duration of the procedure and histological findings has been evaluated.ResultsThere were 10 patients (64 ± 8 years, 6 males). Procedure length was 35min. The specimen area was 9.5mm² (range 3 to 25mm²) and the mean number of alveolar spaces was 29.62. No pneumothorax was registered. 6/10 patients had mild post-biopsy bleeding controlled with standard bronchoscopy measures.ConclusionsThe use of cryoprobes for TBLB may become an alternative technique to increase diagnostic yield.     

The impact of orthodontic treatment on the quality of life in adolescents: a case-control study

The aim of this case-controlled study was to assess the effect of orthodontic treatment on the quality of life of Brazilian adolescents. Two hundred and seventy-nine 'cases' (106 males and 173 females) and 558 controls (246 males and 312 females) were randomly selected from 15- to 16-year-old adolescents attending all secondary schools in Bauru, S?o Paulo, Brazil. A case was defined as having at least one condition-specific impact (CSI) attributed to malocclusion during the previous 6 months, based on the Oral Impact on Daily Performances index. Conversely, a control was defined as having no CSI attributed to malocclusion during the same period. Adolescents were also clinically examined for orthodontic treatment need using the Index of Orthodontic Treatment Need (IOTN) and asked about previous orthodontic treatment. Binary logistic regression was used for statistical analysis. Females and adolescents with a definite normative orthodontic treatment need were more likely to report CSI than males and adolescents with no normative need [odds ratio (OR) = 1.48, 95 per cent confidence interval (CI) = 1.08-2.02 and OR = 2.02, 95 per cent CI = 2.09-4.47, respectively], whereas adolescents with a history of orthodontic treatment were less likely to report CSI than their counterparts (OR = 0.15, 95 per cent CI = 0.07-0.31). Furthermore, there was an interaction between a history of orthodontic treatment and the current level of normative need. Brazilian adolescents with a history of orthodontic treatment were less likely to have physical, psychological, and social impacts on their daily performances associated with malocclusion than those with no history of orthodontics. Gender was a confounding factor, whereas current level of normative orthodontic treatment need was an effect modifier. Prospective studies are needed to corroborate the present findings.