Efficacy of Fluoride Varnish with Casein Phosphopeptide and Amorphous Calcium Phosphate vs Fluoride Varnish in Prevention of White Spots Lesion in fixed Orthodontic Patients: In Vivo Study

AIM

The aim of the study is to compare the in vivo efficiency of Michigan (MI) varnish containing casein phosphopeptide (CPP) and amorphous calcium phosphate (ACP) and Fluoritop containing sodium fluoride (5% NaF) in the prevention and remineralization of white spot lesions (WSLs) around orthodontic brackets at days 28 and 56 after bonding.

MATERIALS AND METHODS

A total of 30 patients were selected and divided into two groups I (MI varnish) II (Fluoritop varnish) of 15 patients in each group. All the patients were bonded and then varnish was applied around the brackets. Right-side upper and lower first premolar teeth were taken as the control group and left-side upper and lower first premolar teeth as the experimental group. Also, 14, 24 teeth were extracted on day 28 after bonding and 34, 44 teeth after day 56 of bonding. Samples were collected and sent to laboratory for evaluation of surface microhardness (SMH).

RESULTS

Based on the statistics results, there was a significant decrease in demineralization and an increase in remineralization of WSLs after the application of varnish. No statistical significance was found between the effectiveness of MI varnish and Fluoritop except in the cervical region.

CONCLUSION

Through our study, we concluded that no statistical significance was found between the effectiveness of MI varnish and Fluoritop except in the cervical region where MI varnish was found to be more effective than Fluoritop in preventing WSLs.

CLINICAL SIGNIFICANCE

The results from the above study concluded that CPP-ACP varnish can be an effective method in preventing WSLs in patients undergoing fixed orthodontic treatment.

Immediate and Delayed Effects of Diode Laser on Debonding of Ceramic Brackets: An in vitro Study

AIM

The aim of the study is to evaluate the immediate and delayed effects of diode laser on debonding of ceramic brackets.

MATERIALS AND METHODS

A total of 60 human extracted premolar teeth were randomly assigned to three different treatment groups. All teeth were bonded with adhesive precoated (APC) ceramic brackets (3M Unitek). A total of 20 teeth were debonded without lasing (group 1), 20 immediately after lasing (group 2), and 20 1 hour after lasing (group 3). For the lasing groups (groups 2 and 3), access cavity was prepared on the occlusal surface to a 2 mm diameter. A transbond plus self-etching primer (3M Unitek, Monrovia, CA, USA) and APC PLUS clarity advanced brackets (3M, Unitek, Monrovia, CA, USA) were used. The shear bond strength (SBS) and adhesive remnant index (ARI) were measured. The internal pulpal wall temperature was noted for the laser groups.

RESULTS

The mean SBS was 15.4, 11.57, and 11.79 MPa for groups 1 to 3 respectively. Post hoc test showed significant difference (p < 0.001) between the control group and the lased groups. For groups 2 and 3, the rise in temperature was at an average of 1.4 and 1.3°C respectively.

CONCLUSION

The SBS of APC brackets decreased by 33.3% on application of diode laser without increasing the internal pulp chamber wall temperature significantly. Shear bond strength remains more or less the same whether debonding is done immediately after lasing or 1 hour after lasing. Diode lasers increased the ARI scores and thus decreased the risk of enamel fracture.

An Accurate Methodology to detect Leaching of Nickel and Chromium Ions in the Initial Phase of Orthodontic Treatment: An in vivo Study

AIM

The aim of this study was to evaluate the release of nickel and chromium ions in human saliva during fixed orthodontic therapy.

MATERIALS AND METHODS

Ten patients with Angle's Class-I malocclusion with bimaxillary protrusion without any metal restorations or crowns and with all the permanent teeth were selected. Five male patients and five female patients in the age group range of 14 to 23 years were scheduled for orthodontic treatment with first premolar extraction. Saliva samples were collected in three stages: sample 1, before orthodontic treatment; sample 2, after 10 days of bonding sample; and sample 3, after 1 month of bonding. The samples were analyzed for the following metals nickel and chromium using inductively coupled plasma optical emission spectrometry (ICP-OES).

RESULTS

The levels of nickel and chromium were statistically significant, while nickel showed a gradual increase in the first 10 days and a decline thereafter. Chromium showed a gradual increase and was statistically significant on the 30th day.

CONCLUSION

There was greatest release of ions during the first 10 days and a gradual decline thereafter. Control group had traces of nickel and chromium. While comparing levels of nickel in saliva, there was a significant rise from baseline to 10th and 30th-day sample, which was statistically significant. While comparing 10th day to that of 30th day, there was no statistical significance. The levels of chromium ion in the saliva were more in 30th day, and when comparing 10th-day sample with 30th day, there was statistical significance.

CLINICAL SIGNIFICANCE

Nickel and chromium levels were well within the permissible levels. However, some hypersensitive individuals may be allergic to this minimal permissible level.

A hard tissue cephalometric comparative study between hand tracing and computerized tracing

Aims:

To analyze and compare the angular and linear hard tissue cephalometric measurements using hand-tracing and computerized tracings with Nemoceph and Dolphin software systems.

Subjects and Methods:

A total of 30 cephalograms were randomly chosen for study with the following criteria, cephalograms of patients with good contrast, no distortion, and minimal radiographic artifacts were considered using the digital method (Kodak 8000 C) with 12 angular and nine linear parameters selected for the study. Comparisons were determined by post-hoc test using Tukey HSD method. The N-Par tests were performed using Kruskal-Walli's method.

Statistical Analysis Used:

ANOVA and post-hoc.

Results:

The results of this study show that there is no significant difference in the angular and linear measurements recorded. The P values were significant at 0.05 levels for two parameters, Co-A and Co-Gn with the hand-tracing method. This was significant in ANOVA and post-hoc test by Tukey HSD method.

Conclusions:

This study of comparison provides support for transition from digital hand to computerized tracing methodology. In fact, digital computerized tracings were easier and less time consuming, with the same reliability irrespective of each method of tracing.

Resistance to simian immunodeficiency virus low dose rectal challenge is associated with higher constitutive TRIM5α expression in PBMC

Background

At least six host-encoded restriction factors (RFs), APOBEC3G, TRIM5α, tetherin, SAMHD1, schlafen 11, and Mx2 have now been shown to inhibit HIV and/or SIV replication in vitro. To determine their role in vivo in the resistance of macaques to mucosally-acquired SIV, we quantified both pre-exposure (basal) and post-exposure mRNA levels of these RFs, Mx1, and IFNγ in PBMC, lymph nodes, and duodenum of rhesus macaques undergoing weekly low dose rectal exposures to the primary isolate, SIV/DeltaB670.

Results

Repetitive challenge divided the monkeys into two groups with respect to their susceptibility to infection: highly susceptible (2–3 challenges, 5 monkeys) and poorly susceptible (≥6 challenges, 3 monkeys). Basal RF and Mx1 expression varied among the three tissues examined, with the lowest expression generally detected in duodenal tissues, and the highest observed in PBMC. The one exception was A3G whose basal expression was greatest in lymph nodes. Importantly, significantly higher basal expression of TRIM5α and Mx1 was observed in PBMC of animals more resistant to mucosal infection. Moreover, individual TRIM5α levels were stable throughout a year prior to infection. Post-exposure induction of these genes was also observed after virus appearance in plasma, with elevated levels in PBMC and duodenum transiently occurring 7–10 days post infection. They did not appear to have an effect on control of viremia. Interestingly, minimal to no induction was observed in the resistant animal that became an elite controller.

Conclusions

These results suggest that constitutively expressed TRIM5α appears to play a greater role in restricting mucosal transmission of SIV than that associated with type I interferon induction following virus entry. Surprisingly, this association was not observed with the other RFs. The higher basal expression of TRIM5α observed in PBMC than in duodenal tissues emphasizes the understated role of the second barrier to systemic infection involving the transport of virus from the mucosal compartment to the blood. Together, these observations provide a strong incentive for a more comprehensive examination of the intrinsic, variable control of constitutive expression of these genes in the sexual transmission of HIV.

9-[4-(Azido-meth-yl)phen-yl]-9H-carbazole-3-carbo-nitrile

In the title compound C₂₀H₁₃N₅, the dihedral angle between the carbazole ring system (r.m.s. deviation = 0.027 Å) and the pendant benzene ring is 55.08 (6)°. One of the azide N atoms is disordered over two positions in a 0.65 (2):0.35 (2) ratio. In the crystal, aromatic π–π stacking is observed [minimum centroid–centroid separation = 3.6499 (13) Å] as well as inversion-dimers connected by pairs of weak C—H⋯π inter­actions.

1-[6-(1H-Indol-1-yl)pyridin-2-yl]-1H-indole-3-carbaldehyde

In the title compound, C₂₂H₁₅N₃O, the dihedral angle between the two indole units is 33.72 (3)°. The mol­ecular structure features a weak intra­molecular C—H⋯N inter­action. In the crystal, weak C—H⋯O and C—H⋯π inter­actions, forming a two-dimensional network parallel to the bc plane.

Response of simian immunodeficiency virus to the novel nucleoside reverse transcriptase inhibitor 4'-ethynyl-2-fluoro-2'-deoxyadenosine in vitro and in vivo

Nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) are essential components in first-line therapy for human immunodeficiency virus (HIV) infection. However, long-term treatment with existing NRTIs can be associated with significant toxic side effects and the emergence of drug-resistant strains. The identification of new NRTIs for the continued management of HIV-infected people therefore is paramount. In this report, we describe the response of a primary isolate of simian immunodeficiency virus (SIV) to 4'-ethynyl-2-fluoro-2'-deoxyadenosine (EFdA) both in vitro and in vivo. EFdA was 3 orders of magnitude better than tenofovir (TFV), zidovudine (AZT), and emtricitabine (FTC) in blocking replication of SIV in monkey peripheral blood mononuclear cells (PBMCs) in vitro, and in a preliminary study using two SIV-infected macaques with advanced AIDS, it was highly effective at treating SIV infection and AIDS symptoms in vivo. Both animals had 3- to 4-log decreases in plasma virus burden within 1 week of EFdA therapy (0.4 mg/kg of body weight, delivered subcutaneously twice a day) that eventually became undetectable. Clinical signs of disease (diarrhea, weight loss, and poor activity) also resolved within the first month of treatment. No detectable clinical or pathological signs of drug toxicity were observed within 6 months of continuous therapy. Virus suppression was sustained until drug treatment was discontinued, at which time virus levels rebounded. Although the rebound virus contained the M184V/I mutation in the viral reverse transcriptase, EFdA was fully effective in maintaining suppression of mutant virus throughout the drug treatment period. These results suggest that expanded studies with EFdA are warranted.

Transcription factor expression profiling to characterize differentiation of antigen-specific CD8 T cells induced by a live attenuated viral vaccine. (113.18)

Live attenuated SIV (SIVΔnef) is the most effective approach to induce protection to pathogenic SIV challenge in macaques. Protective immunity, in part mediated by CD8 T cell responses, correlates with phenotypic maturation of SIV-specific T cells, but remains incompletely understood. Expression profiling of T cell transcription factors (TF) offers a novel approach to characterize antigen-specific T cell differentiation. Highly parallel qRT-PCR was used to characterize the expression of 21 TF in naïve, central, transitional, and effector memory T cell subsets, and in SIV-specific CD8 T cells obtained at times associated with lesser protection (wk 5) and greater protection (wk 20) following SIVΔnef vaccination. Unsupervised clustering organized samples from CD4 and CD8 T cells into groups concordant with cell surface phenotype. TF expression in SIV-specific CD8+ T cells segregated by time, with wk 20 cells exhibiting increased expression of TF associated with both maintenance of quiescence (TCF7, BAZF) and promotion of effector function (Eomes, T-Bet). Different expression profiles were observed in T cells specific for different SIV epitopes, consistent with different epitope escape kinetics. TF expression profiling suggests T cell responses correlated with protection may include characteristics of both memory and effector cells. TF expression profiling can provide data complementary to the analysis of memory cell differentiation based on classical phenotypic markers.

Therapeutic DNA vaccine induces broad T cell responses in the gut and sustained protection from viral rebound and AIDS in SIV-infected rhesus macaques

Immunotherapies that induce durable immune control of chronic HIV infection may eliminate the need for life-long dependence on drugs. We investigated a DNA vaccine formulated with a novel genetic adjuvant that stimulates immune responses in the blood and gut for the ability to improve therapy in rhesus macaques chronically infected with SIV. Using the SIV-macaque model for AIDS, we show that epidermal co-delivery of plasmids expressing SIV Gag, RT, Nef and Env, and the mucosal adjuvant, heat-labile E. coli enterotoxin (LT), during antiretroviral therapy (ART) induced a substantial 2-4-log fold reduction in mean virus burden in both the gut and blood when compared to unvaccinated controls and provided durable protection from viral rebound and disease progression after the drug was discontinued. This effect was associated with significant increases in IFN-γ T cell responses in both the blood and gut and SIV-specific CD8+ T cells with dual TNF-α and cytolytic effector functions in the blood. Importantly, a broader specificity in the T cell response seen in the gut, but not the blood, significantly correlated with a reduction in virus production in mucosal tissues and a lower virus burden in plasma. We conclude that immunizing with vaccines that induce immune responses in mucosal gut tissue could reduce residual viral reservoirs during drug therapy and improve long-term treatment of HIV infection in humans.

9-p-Tolyl-9H-carbazole-3-carbonitrile

In the title compound, C₂₀H₁₄N₂, the carbazole ring system is essentially planar (r.m.s. deviation = 0.187 Å) and is inclined at an angle of 54.33 (4) ° with respect to the benzene ring. The crystal packing is stabilized by weak C—H⋯N and C—H⋯π inter­actions.

(E)-1-[4-(Prop-2-yn-1-yl-oxy)phen-yl]-3-(3,4,5-trimeth-oxy-phen-yl)prop-2-en-1-one

The mol­ecule of the title chalcone derivative, C₂₁H₂₀O₅, consists of two substituted aromatic rings bridged by a prop-2-en-1-one group. The dihedral angle between the two benzene rings is 28.7 (7)°. In the crystal, mol­ecules are linked into C(10) chains running along the a axis by inter­molecular C—H⋯O hydrogen bonds, and the chains are cross-linked via C—H⋯π inter­actions.

Trauma from occlusion - An orthodontist′s perspective

Orthodontic therapy has a big role in the treatment and prevention of malpositions. The signs and symptoms experienced by patients with occlusal trauma are mobility of teeth, temperomandibular joint pain, pain on mastication and periodontal disease. Early diagnosis, proper treatment plan and correction of malocclusion can lead to a successful outcome. Lack of awareness of orthodontic treatment in patients with occlusal trauma can even lead to loss of tooth structure.

4,5-Bis(1H-imidazol-1-ylmeth-yl)acridine monohydrate

In the title compound, C(21)H(17)N(5)·H(2)O, the dihedral angles between the acridine ring system and the imidazole rings are 78.8 (1) and 71.2 (1)°. The crystal packing is stabilized by O-H⋯N, C-H⋯O, C-H⋯π and π-π inter-actions [centroid-centroid separations = 3.732 (1) and 3.569 (1) Å].

Restricted SIV replication in rhesus macaque lung tissues during the acute phase of infection

The extent to which simian immunodeficiency virus (SIV) replication in lung tissues contributes to the pool of viruses replicating during acute infection is incompletely understood. To address this issue, in situ hybridization was used to examine SIV replication in multiple lobes of lung from rhesus macaques infected with pathogenic SIV. Despite widespread viral replication in lymphoid and intestinal tissues, the lungs during acute infection harbored rare productively infected cells. Simultaneous immunohistochemical staining for the monocytic marker, CD68, revealed that SIV RNA(+) cells in lung tissues during acute infection were CD68(-), whereas during AIDS they were predominantly CD68(+) and localized in large foci in caudal lobes. SIV RNA(+) cells in spleen remained CD68(-) throughout disease. Since CD68 is also expressed by subpopulations of dendritic cells (DC), we also examined pulmonary CD68(+) cells for expression of additional DC markers. DC-LAMP mRNA was abundant in lung tissues and expressed predominantly by CD68(-) cells, whereas DC-SIGN mRNA was expressed in only very rare cells, indicating that SIV RNA(+) cells late in disease were most likely macrophages. These studies of SIV/host interactions demonstrate that macaque lung tissues are minimally infected during acute infection, exhibit changes in predominant target cells for infection, and express very little DC-SIGN.

Increased expression of the inflammatory chemokine CXC chemokine ligand 9/monokine induced by interferon-gamma in lymphoid tissues of rhesus macaques during simian immunodeficiency virus infection and acquired immunodeficiency syndrome

Chemokines are important mediators of cell trafficking during immune inductive and effector activities, and dysregulation of their expression might contribute to the pathogenesis of human immunodeficiency virus type 1 and the related simian immunodeficiency virus (SIV). To understand better the effects of SIV infection on lymphoid tissues in rhesus macaques, we examined chemokine messenger RNA (mRNA) expression patterns by using DNA filter array hybridization. Of the 34 chemokines examined, the interferon gamma (IFN-gamma)-inducible chemokine CXC chemokine ligand 9/monokine induced by interferon-gamma (CXCL9/Mig) was one of the most highly up-regulated chemokines in rhesus macaque spleen tissue early after infection with pathogenic SIV. The relative levels of expression of CXCL9/Mig mRNA in spleen and lymph nodes were significantly increased after infection with SIV in both quantitative image capture and analysis and real-time reverse transcriptase-polymerase chain reaction assays. In addition, in situ hybridization for CXCL9/Mig mRNA revealed that the patterns of expression were altered after SIV infection. Associated with the increased expression of CXCL9/Mig were increased numbers of IFN-gamma mRNA-positive cells in tissues and reduced percentages of CXC chemokine receptor (CXCR) 3(+)/CD3(+) and CXCR3(+)/CD8(+) lymphocytes in peripheral blood. We propose that SIV replication in vivo initiates IFN-gamma-driven positive-feedback loops in lymphoid tissues that disrupt the trafficking of effector T lymphocytes and lead to chronic local inflammation, thereby contributing to immunopathogenesis.

Evidence for intracellular down-regulation of the epidermal growth factor (EGF) receptor during adenovirus infection by an EGF-independent mechanism

We have reported previously that human group C adenoviruses down-regulate the epidermal growth factor (EGF) receptor (EGF-R) (C. R. Carlin, A. E. Tollefson, H. A. Brady, B. L. Hoffman, and W. S. M. Wold, Cell 57:135-144, 1989). Expression of a 13.7-kDa protein encoded by a gene in the E3 transcription unit is necessary and sufficient for this effect (Carlin et al., Cell, 1989; B. L. Hoffman, A. Ullrich, W. S. M. Wold, and C. R. Carlin, Mol. Cell. Biol. 10:5521-5524, 1990). We show here that EGF-R down-regulation is accelerated in cells which overexpress the receptor when these cells are infected with virus mutants that overproduce the 13.7-kDa protein compared with wild-type virus. This is in contrast to EGF stimulation, for which others have shown that high concentrations of ligand are associated with low rates of receptor internalization in EGF-R-overexpressing cells (D. Kuppuswamy and L. J. Pike, J. Biol. Chem. 264:3357-3363, 1989; H. S. Wiley, J. Cell Biol. 107:801-810, 1988). We also show that the E3 protein is not present in media conditioned by infected cells and that it does not induce secretion of an EGF-like autocrine factor. Moreover, while mature membrane-bound EGF-R is down-regulated, the precursor of the membrane-bound form is not. Adenovirus infection also does not affect receptor-related molecules expressed in the secretory pathway. Interestingly, adenovirus-induced down-regulation is not regulated by concentrations of EGF associated with a slow rate of internalization in A431 cells. This suggests that 13.7-kDa protein expression triggers receptor entry by a novel ligand-independent pathway or, alternatively, that it compensates for a cellular factor that may be rate limiting during EGF-mediated endocytosis.