Load-deflection characteristics of coated and noncoated nickel-titanium wires in self-ligating brackets using a modified bending test: An in vitro study.

BACKGROUND: To determine and compare the force-deflection values of different types of nickel-titanium (NiTi) wires during unloading phase at varying deflections, that is 1 mm, 1.5 mm, 2 mm, and 2.5 mm, with the use of self-ligating ceramic brackets using modified bending test on a typodont under controlled temperature conditions. MATERIALS AND METHODS: In this in vitro study total of 45 wires of ovoid shape of three different NiTi wires - pseudoelastic NiTi (Group I), heat activated NiTi (Group II), and esthetic coated NiTi (Group III) for maxillary arch were tested after insertion in ceramic self-ligating brackets bonded to plastic teeth of phantom jaw. The maxillary left lateral incisor was removed to simulate a malpositioned tooth which acted as the load site, and load-deflection characteristics were measured during unloading using Instron, and data analyzed statically by two-way analysis of variance, Tukey's post hoc test, intraclass correlation coefficient and Pearson correlation coefficient. A two-sided (α = 2) P < 0.05 was considered statistically significant. RESULTS: When wires were compared at each deflection statistically significant difference was observed between the three groups of wires (Group I > Group II > Group III) at all the four levels of deflection except for Group II versus Group III at 1 mm, 1.5 mm, and 2 mm of deflection. Statistically significant difference was noted in mean load values for comparisons made at different deflections for each wire except for the comparison made at 1.5 versus 2 mm for Group II and Group III. CONCLUSION: Overall comparison showed esthetic coated Ni-Ti wires gave significantly lower mean load values, followed by heat activated and pseudoelastic NiTi wires. Thus, heat activated NiTi wires are best suited in patients with severe malpositions/periodontitis, while for esthetically conscious patients esthetic coated NiTi can be used.

Dimensional and volumetric analysis of the oropharyngeal region in obstructive sleep apnea patients: A cone beam computed tomography study.

BACKGROUND: Obstructive Sleep Apnea (OSA) is a potentially life-threatening condition in which there is a periodic cessation of breathing (for 10 sec or longer) that occurs during sleep in the presence of inspiratory effort. The aim of the study was to assess volumetric and dimensional differences between OSA patients and normal individuals in the upright posture. MATERIAL AND METHOD: The present study was conducted on CBCT scans of 32 patients who were divided into two groups -Group I (control group) and Group II (OSA subjects). Group I consisted of 16 patients with normal airway with ESS score from 2 to 10, STOP BANG Questionnaire score of <3 and who had undergone CBCT for various diagnostic reasons. Group II had patients with ESS score >10, STOP BANG Questionnaire score of > 3, AHI index >5. Linear and angular parameters, volume and minimum cross-section area (MCA) of oropharyngeal airway, anteroposterior length and lateral width at MCA was compared amongst the groups. RESULTS: The oropharyngeal volume, MCA, and the anteroposterior and lateral width of the airway at MCA of the OSA subjects was significantly lesser than that of normal subjects. The length of both soft palate and tongue was significantly more in Group II. The angle between the nasopharyngeal airway and the oropharyngeal airway was significantly more obtuse in Group II. CONCLUSION: The reduction in oropharyngeal volume in OSA patients could be attributed to different anatomical and pathophysiological factors that were corroborated with the findings of the present study.

A cephalometric evaluation of the effect of glenoid fossa location on craniofacial morphology.

AIM: The purpose of this study was to assess the effect of glenoid fossa location in various skeletal malocclusions on craniofacial morphology. METHODS: Cephalometric data of 84 subjects were analyzed for four linear and two angular variables for assessing glenoid fossa location in cranial base and eight linear and eight angular variables for evaluating the corresponding effect on craniofacial morphology using statistical software STATA 12 for windows. Regression analysis was done to see the effect of glenoid fossa location on the parameters measuring craniofacial morphology. RESULTS: Significant association between glenoid fossa location and craniofacial morphology was demonstrated in skeletal class I, class II, and class III malocclusion subjects by the regression analysis. CONCLUSIONS: Glenoid fossa location varies significantly among skeletal malocclusions and glenoid fossa location has a profound effect on craniofacial morphology of skeletal class I, class II, and class III malocclusions.

Perioperative management of a patient with left ventricular dysfunction and anomalous coronary arteries.

Anesthetic management of patients with coronary artery disease undergoing noncardiac surgery is quite challenging. Such patients are at increased risk of perioperative cardiac complications and death. We report an illustrative case of a 62-year-old male with ischemic heart disease and anomalous coronary arteries for obstructed paraumbilical hernia repair.

Extracellular galectin-3 induces MMP9 expression by activating p38 MAPK pathway via lysosome-associated membrane protein-1 (LAMP1).

Matrix metalloproteinases (MMPs) play a key role in matrix remodelling and thus invasion and metastasis. Extracellular galectin-3 has been shown to induce MMP9 secretion. Here, we demonstrate that galectin-3 induces MMP9 at transcript level and it is dependent on the surface levels of poly-N-acetyllactosamine (polyLacNAc). By employing signalling pathway inhibitors, MMP9 expression was shown to be induced via p38 MAP-kinase pathway. Using clones of melanoma cells expressing shRNAs to lysosome-associated membrane protein-1 (LAMP1), a major carrier of polyLacNAc, surface LAMP1 was demonstrated to serve as one of the key mediators of galectin-3-induced MMP9 expression via p38 MAPK pathway.

Role of tumor cell surface lysosome-associated membrane protein-1 (LAMP1) and its associated carbohydrates in lung metastasis.

PURPOSE: Expression of lysosome-associated membrane protein-1 (LAMP1) on the surface correlates with metastatic potential of B16 melanoma cells. Downregulation of their expression in high metastatic (B16F10) cells reduced their surface expression and metastatic potential. Present investigations explore if overexpression of LAMP1 on the surface of low metastatic (B16F1) cells augment their metastatic ability, and if so, how? METHODS: B16F1 cells were transduced with lentiviral vector carrying mutant-LAMP1 (Y386A) (mutLAMP1). Surface expression of LAMP1 and carbohydrates was analyzed by flow cytometry, immunofluorescence and/or immunoprecipitation and Western blotting. Cell spreading and motility were assessed on components of extracellular matrix (ECM) (fibronectin) and basement membrane (BM) (matrigel), and galectin-3-coated coverslips/plates. Metastatic potential was assessed using experimental metastasis assay. RESULTS: Pre-incubation with anti-LAMP1 antibodies significantly reduced lung metastasis of B16F10 cells. Overexpression of mutLAMP1 significantly increased its surface expression on B16F1 cells, resulting in increased cellular spreading and motility on fibronectin and matrigel. LAMP1 is the major carrier of poly-N-acetyllactosamine (polyLacNAc) on B16F10 cells. However, significantly higher expression of mutLAMP1 had no effect on galectin-3 binding on cell surface or on spreading or motility of cells on galectin-3-coated coverslips/plates. These cells also failed to show any gain in metastatic ability. This could be because LAMP1 from these cells carried significantly lower levels of polyLacNAc in comparison with B16F10 cells. CONCLUSIONS: PolyLacNAc on B16F10 cells and galectin-3 on lungs are the major participants in melanoma metastasis. Although surface LAMP1 promotes interactions with organ ECM and BM, carbohydrates on LAMP1 play a decisive role in dictating lung metastasis.

Cardiovascular risks associated with low dose ionizing particle radiation.

Previous epidemiologic data demonstrate that cardiovascular (CV) morbidity and mortality may occur decades after ionizing radiation exposure. With increased use of proton and carbon ion radiotherapy and concerns about space radiation exposures to astronauts on future long-duration exploration-type missions, the long-term effects and risks of low-dose charged particle irradiation on the CV system must be better appreciated. Here we report on the long-term effects of whole-body proton ((1)H; 0.5 Gy, 1 GeV) and iron ion ((56)Fe; 0.15 Gy, 1GeV/nucleon) irradiation with and without an acute myocardial ischemia (AMI) event in mice. We show that cardiac function of proton-irradiated mice initially improves at 1 month but declines by 10 months post-irradiation. In AMI-induced mice, prior proton irradiation improved cardiac function restoration and enhanced cardiac remodeling. This was associated with increased pro-survival gene expression in cardiac tissues. In contrast, cardiac function was significantly declined in (56)Fe ion-irradiated mice at 1 and 3 months but recovered at 10 months. In addition, (56)Fe ion-irradiation led to poorer cardiac function and more adverse remodeling in AMI-induced mice, and was associated with decreased angiogenesis and pro-survival factors in cardiac tissues at any time point examined up to 10 months. This is the first study reporting CV effects following low dose proton and iron ion irradiation during normal aging and post-AMI. Understanding the biological effects of charged particle radiation qualities on the CV system is necessary both for the mitigation of space exploration CV risks and for understanding of long-term CV effects following charged particle radiotherapy.

The effect of central incisor's root proximity to the cortical plate and apical root resorption in extraction and non-extraction treatment.

AIMS: The present study was conducted to investigate the relevance of cortical plate proximity of maxillary central incisor root, maxillary alveolar bone width, and the apical root resorption in extraction and non-extraction orthodontically treated cases. Further, the correlation between the apical root resorption and the various parameters was investigated. MATERIALS AND METHODS: A total of 80 lateral head cephalographs, 40 pre-treatment and 40 post-treatment, of orthodontic subjects with a mean age of 15 years treated with fixed standard edgewise appliance were obtained. All subjects were divided into two groups as extraction and non-extraction cases. Twelve linear and three angular parameters were measured and evaluated. The paired "t"-test, Pearson's correlation coefficient, and the stepwise regression analysis were done to test the relationship between the apical root resorption and the various parameters. RESULTS AND CONCLUSIONS: The study revealed slightly greater amount of apical root resorption in extraction subjects as compared to non-extraction subjects. However, no statistically significant difference was found between the two treatment modalities. In extraction subjects, the apical root resorption was directly proportional to the pre-treatment length of maxillary central incisor and inversely proportional to the root width in apical one-third region, though there was a weak correlation. In non-extraction subjects, the pre-treatment anteroposterior position of the root apex of maxillary central incisor in the alveolar bone, in combination with its root width in the apical one-third region formed the predictive factors for the variance in the amount of the apical root resorption, though there was a weak correlation. Furthermore, the changes in the alveolar widths at the root apex and mid-root region were considered as predictive factors for the amount of apical root resorption during extraction and non-extraction treatment, respectively.

Regulation of melanoma metastasis to lungs by cell surface Lysosome Associated Membrane Protein-1 (LAMP1) via galectin-3.

Lysosome Associated Membrane Protein-1 (LAMP1), which lines the lysosomes, is often found to be expressed on surface of metastatic cells. We previously demonstrated that its surface expression on B16 melanoma variants correlates with metastatic potential. To establish the role of cell surface LAMP1 in metastasis and to understand the possible mechanism by which it facilitates lung colonization, LAMP1 was downregulated in high metastatic B16F10 cells using shRNAs cloned in a doxycycline inducible vector. This also resulted in significantly decreased LAMP1 on the cell surface. Being a major carrier of poly-N-acetyllactosamine (polyLacNAc) substituted ß1,6 branched N-oligosaccharides, the high affinity ligands for galectin-3, LAMP1 down regulation also resulted in appreciably decreased binding of galectin-3 to the cell surface. LAMP1 has been shown to bind to Extracellular Matrix (ECM), Basement Membrane (BM) components and also to galectin-3 (via carbohydrates) which is known to get incorporated into the ECM and BM. Although, LAMP1 downregulation had a marginal effect on cellular spreading and motility on fibronectin and matrigel, it significantly altered the same on galectin-3, and ultimately leading to notably reduced lung metastasis. The results thus for the first time provide direct evidence that cell surface LAMP1 facilitates lung metastasis by providing ligands for galectin-3 which has been shown to be expressed in highest amounts on lungs and constitutively on its vascular endothelium.

Divergent modification of low-dose 56Fe-particle and proton radiation on skeletal muscle.

It is unknown whether loss of skeletal muscle mass and function experienced by astronauts during space flight could be augmented by ionizing radiation (IR), such as low-dose high-charge and energy (HZE) particles or low-dose high-energy proton radiation. In the current study adult mice were irradiated whole-body with either a single dose of 15 cGy of 1 GeV/n 56Fe-particle or with a 90 cGy proton of 1 GeV/n proton particles. Both ionizing radiation types caused alterations in the skeletal muscle cytoplasmic Ca²âº ([Ca²âº]i) homeostasis. 56Fe-particle irradiation also caused a reduction of depolarization-evoked Ca²âº release from the sarcoplasmic reticulum (SR). The increase in the [Ca²âº]i was detected as early as 24 h after 56Fe-particle irradiation, while effects of proton irradiation were only evident at 72 h. In both instances [Ca²âº]i returned to baseline at day 7 after irradiation. All 56Fe-particle irradiated samples revealed a significant number of centrally localized nuclei, a histologic manifestation of regenerating muscle, 7 days after irradiation. Neither unirradiated control or proton-irradiated samples exhibited such a phenotype. Protein analysis revealed significant increase in the phosphorylation of Akt, Erk1/2 and rpS6k on day 7 in 56Fe-particle irradiated skeletal muscle, but not proton or unirradiated skeletal muscle, suggesting activation of pro-survival signaling. Our findings suggest that a single low-dose 56Fe-particle or proton exposure is sufficient to affect Ca²âº homeostasis in skeletal muscle. However, only 56Fe-particle irradiation led to the appearance of central nuclei and activation of pro-survival pathways, suggesting an ongoing muscle damage/recovery process.

Latent lip print development and its role in suspect identification.

AIMS AND OBJECTIVE: The study aims to develop latent lip prints on glass surface using fingerprint black powder and its comparison with standard lipstick prints and also determines the effectiveness of the technique. MATERIALS AND METHODS: This study included a total of 100 subjects, comprising of 50 males and 50 females with age ranging from 17 to 38 years. Latent lipprint was developed by pressing the lips against a glass slab with lips together and the print formed was developed by sprinkling the black finger print powder and transferred to a bond sheet. Subsequently, standard lipstick print was developed from the same subject. All the samples were coded and graded according to the patterns suggested in the literature. RESULTS: Out of 100 latent prints only 29 prints showed lip patterns in all four quadrants. The percentage matching with self lipstick print of good latent prints ranged from 25% to 100% and those of random prints ranged from 8% to 92%. Quadrant wise matching ranged from 52.67% to 57.67%. Statistically significant difference was observed between males and females. CONCLUSION: The study demonstrates the usefulness of latent lip print in personal identification.

Suprabasal expression of Ki-67 as a marker for the severity of oral epithelial dysplasia and oral squamous cell carcinoma.

BACKGROUND: Transition of the normal oral epithelium to dysplasia and to malignancy is featured by increased cell proliferation. To evaluate the hypothesis of distributional disturbances in proliferating and stem cells in oral epithelial dysplasia and oral squamous cell carcinoma (OSCC). AIM: To evaluate layer wise expression of Ki-67 in oral epithelial dysplasia and in OSCC. MATERIALS AND METHODS: Thirty histologically confirmed cases of oral epithelial dysplasia, fifteen cases of OSCC and five cases of normal buccal mucosa were immunohistochemically examined and nuclear expression of Ki-67 was counted according to basal, parabasal, and suprabasal layers in epithelial dysplasia and number of positive cells per 100 cells in OSCC as labeling index (LI). RESULTS: Suprabasal expression of Ki-67 increased according to the severity of epithelial dysplasia and the difference was statistically significant (P < 0.001). The mean Ki-67LI was 12.78 for low risk lesions, 28.68 for high risk lesions, 39.45 for OSCC and 13.6 for normal buccal mucosa. CONCLUSION: The results of the present study demonstrate the use of proliferative marker Ki-67 in assessing the severity of epithelial dysplasia. Suprabasal expression of Ki-67 provides an objective criteria for determining the severity of epithelial dysplasia and histological grading of OSCC.

A new proposed regression equation for mixed dentition analysis using the sum of permanent mandibular four incisors and first molar as a predictor of width of unerupted canine and premolars in a sample of North Indian population.

OBJECTIVE: The objective of this study was to establish a new regression equation for North Indian and to compare and correlate the predicted width of unerupted canine and premolars obtained from the proposed regression equation of the present study in the North Indian population sample, Moyer's prediction table and also from Melgaco regression equation with the actual width; in order to check the applicability of various methods of mixed dentition analysis for the North Indian population. MATERIALS AND METHODS: The sample consisted of 200 dental casts obtained from the North Indian patients and students which consists of 100 males and 100 females with the average age of 20.12 ± 4.70 years for males and 19.54 ± 3.16 years for females. Mesiodistal tooth widths of mandibular arch from permanent right first molar to left first molar were measured with an electronic digital caliper. Student t-test was used for comparison and Pearson's correlation coefficient was used to correlate the actual sum and the predicted width of the permanent mandibular canines and premolars obtained from various methods. RESULTS: The difference between the actual and predicted width was statistically insignificant using the regression equation obtained for the North Indian sample population (correlation r = 0.78) in contrast to the significant difference with predicted width obtained from Melgaco equation (r = 0.61) and Moyer's prediction table (r = 0.42). CONCLUSIONS: A new proposed regression equation for the North Indian population was established. Amongst the three regression equations devised, the proposed regression equation formulated in the present study; gave the most accurate results confirming racial variation in tooth size. This method is considered as an easy and practical way to predict the size of unerupted canines and premolars.