Determining of canine position by multiple facial landmarks to achieve natural esthetics in complete denture treatment.

STATEMENT OF PROBLEM: Anterior tooth selection is an important step in complete denture treatment as it plays a pivotal role not only in esthetics but also in mastication and pronunciation. However, conventional methods for tooth selection are not well established and rely on facial measurements and proportions, which vary among different ethnicities. PURPOSE: The purpose of this clinical study was to investigate the relationship between interalar width and intercanine distance and to compare different clinical methods for determining the position of the canine tooth. MATERIAL AND METHODS: Two hundred Thai participants (100 men and 100 women) aged 18 to 25 years with 6 full maxillary anterior teeth were enrolled in this study. The interalar width and intercanine distance were measured with digital vernier calipers and compared by using the paired-samples t test. To determine the canine position, 2 reference lines-the alar line (A line) and the inner canthus of the eye to alar line (IA line)-were drawn through the canine on both sides. The horizontal distances from each reference line to the canine cusp tip and distal contact point were evaluated and then analyzed using the 1-sample t test. RESULTS: All measurements were significantly different between men and women (P<.01). Interalar width was greater than intercanine distance in both sexes. In men, the A line coincided with the canine distal contact point (P>.05). In contrast, the IA line was distal to the canine distal contact point by 3.5 ±3.6 mm on the left side and by 3.9 ±3.4 mm on the right side. In women, the A line was situated between the canine cusp tip and distal contact point. It was mesial to the distal contact point by 2.0 ±2.0 mm on the left side and by 1.8 ±2.0 mm on the right side. The IA line was distal to the canine distal contact point by 1.2 ±2.6 mm on the left side and by 1.6 ±2.7 mm on the right side. CONCLUSIONS: The interalar width is greater than the intercanine distance in both sexes. The A line is more clinically relevant than the IA line for predicting canine position. The A line can directly determine the distal contact point of the canine in edentulous male patients. However, in women, a distance of approximately 2 mm should be added distal to the A line to locate the distal contact point of the canine on both sides.

Early mucosal sensing of SIV infection by paneth cells induces IL-1ß production and initiates gut epithelial disruption.

HIV causes rapid CD4+ T cell depletion in the gut mucosa, resulting in immune deficiency and defects in the intestinal epithelial barrier. Breakdown in gut barrier integrity is linked to chronic inflammation and disease progression. However, the early effects of HIV on the gut epithelium, prior to the CD4+ T cell depletion, are not known. Further, the impact of early viral infection on mucosal responses to pathogenic and commensal microbes has not been investigated. We utilized the SIV model of AIDS to assess the earliest host-virus interactions and mechanisms of inflammation and dysfunction in the gut, prior to CD4+ T cell depletion. An intestinal loop model was used to interrogate the effects of SIV infection on gut mucosal immune sensing and response to pathogens and commensal bacteria in vivo. At 2.5 days post-SIV infection, low viral loads were detected in peripheral blood and gut mucosa without CD4+ T cell loss. However, immunohistological analysis revealed the disruption of the gut epithelium manifested by decreased expression and mislocalization of tight junction proteins. Correlating with epithelial disruption was a significant induction of IL-1ß expression by Paneth cells, which were in close proximity to SIV-infected cells in the intestinal crypts. The IL-1ß response preceded the induction of the antiviral interferon response. Despite the disruption of the gut epithelium, no aberrant responses to pathogenic or commensal bacteria were observed. In fact, inoculation of commensal Lactobacillus plantarum in intestinal loops led to rapid anti-inflammatory response and epithelial tight junction repair in SIV infected macaques. Thus, intestinal Paneth cells are the earliest responders to viral infection and induce gut inflammation through IL-1ß signaling. Reversal of the IL-1ß induced gut epithelial damage by Lactobacillus plantarum suggests synergistic host-commensal interactions during early viral infection and identify these mechanisms as potential targets for therapeutic intervention.

Covalent Chemical Ligation Strategy for Mono- and Polyclonal Immunoglobulins at Their Nucleotide Binding Sites.

Nonspecific ligation methods have been traditionally used to chemically modify immunoglobulins. Site-specific ligation of compounds (toxins or ligands) to antibodies has become increasingly important in the fields of therapeutic antibody-drug conjugates and bispecific antibodies. In this present study, we took advantage of the reported nucleotide-binding pocket (NBP) in the Fab arms of immunoglobulins by developing indole-based, 5-fluoro-2,4-dinitrobenzene-derivatized OBOC peptide libraries for the identification of affinity elements that can be used as site-specific derivatization agents against both mono- and polyclonal antibodies. Ligation can occur at any one of the few lysine residues located at the NBP. Immunoconjugates resulting from such affinity elements can be used as therapeutics against cancer or infectious agents.

Engineering clustered ligand binding into nonviral vectors: alphavbeta3 targeting as an example.

The development of techniques to efficiently deliver genes using nonviral approaches can broaden the application of gene delivery in medical applications without the safety concerns associated with viral vectors. Here, we designed a clustered integrin-binding platform to enhance the efficiency and targetability of nonviral gene transfer to HeLa cells with low and high densities of alpha(v)beta(3) integrin receptors. Arg-Gly-Asp (RGD) nanoclusters were formed using gold nanoparticles functionalized with RGD peptides and used to modify the surface of DNA/poly(ethylene imine) (PEI) polyplexes. DNA/PEI polyplexes with attached RGD nanoclusters resulted in either 5.4- or 35-fold increase in gene transfer efficiency over unmodified polyplexes for HeLa cells with low- or high-integrin surface density, respectively. The transfection efficiency obtained with the commercially available vector jetPEI-RGD was used for comparison as a vector without clustered binding. JetPEI-RGD exhibited a 1.2-fold enhancement compared to unmodified jetPEI in cells with high densities of alpha(v)beta(3) integrin receptors. The data presented here emphasize the importance of the RGD conformational arrangement on the surface of the polyplex to achieve efficient targeting and gene transfer, and provide an approach to introduce clustering to a wide variety of nanoparticles for gene delivery.

Encapsulation and delivery of plasmid DNA by virus-like nanoparticles engineered from Macrobrachium rosenbergii nodavirus.

Virus-like particles (VLPs) are potential candidates in developing biological containers for packaging therapeutic or biologically active agents. Here, we expressed Macrobrachium rosenbergii nodavirus (MrNv) capsid protein (encoding amino acids M1-N371 with 6 histidine residuals) in an Escherichia coli BL21(DE3). These easily purified capsid protein self-assembled into VLPs, and disassembly/reassembly could be controlled in a calcium-dependent manner. Physically, MrNv VLPs resisted to digestive enzymes, a property that should be advantageous for protection of active compounds against harsh conditions. We also proved that MrNv VLPs were capable of encapsulating plasmid DNA in the range of 0.035-0.042 mol ratio (DNA/protein) or 2-3 plasmids/VLP (assuming that MrNV VLPs is T=1, i made up of 60 capsid monomers). These VLPs interacted with cultured insect cells and delivered loaded plasmid DNA into the cells as shown by green fluorescent protein (GFP) reporter. With many advantageous properties including self-encapsulation, MrNv VLPs are good candidates for delivery of therapeutic agents.

"OA02" peptide facilitates the precise targeting of paclitaxel-loaded micellar nanoparticles to ovarian cancer in vivo.

Micellar nanoparticles based on linear polyethylene glycol (PEG) block dendritic cholic acids (CA) copolymers (telodendrimers), for the targeted delivery of chemotherapeutic drugs in the treatment of cancers, are reported. The micellar nanoparticles have been decorated with a high-affinity "OA02" peptide against α-3 integrin receptor to improve the tumor-targeting specificity which is overexpressed on the surface of ovarian cancer cells. "Click chemistry" was used to conjugate alkyne-containing OA02 peptide to the azide group at the distal terminus of the PEG chain in a representative PEG(5k)-CA(8) telodendrimer (micelle-forming unit). The conjugation of OA02 peptide had negligible influence on the physicochemical properties of PEG(5k)-CA(8) nanoparticles and as hypothesized, OA02 peptide dramatically enhanced the uptake efficiency of PEG(5k)-CA(8) nanoparticles (NP) in SKOV-3 and ES-2 ovarian cancer cells via receptor-mediated endocytosis, but not in α-3 integrin-negative K562 leukemia cells. When loaded with paclitaxel, OA02-NPs had significantly higher in vitro cytotoxicity against both SKOV-3 and ES-2 ovarian cancer cells as compared with nontargeted nanoparticles. Furthermore, the in vivo biodistribution study showed OA02 peptide greatly facilitated tumor localization and the intracellular uptake of PEG(5k)-CA(8) nanoparticles into ovarian cancer cells as validated in SKOV3-luc tumor-bearing mice. Finally, paclitaxel (PTX)-loaded OA02-NPs exhibited superior antitumor efficacy and lower systemic toxicity profile in nude mice bearing SKOV-3 tumor xenografts, when compared with equivalent doses of nontargeted PTX-NPs as well as clinical paclitaxel formulation (Taxol). Therefore, OA02-targeted telodendrimers loaded with paclitaxel have great potential as a new therapeutic approach for patients with ovarian cancer.

Zernike phase plate cryoelectron microscopy facilitates single particle analysis of unstained asymmetric protein complexes.

Single particle reconstruction from cryoelectron microscopy images, though emerging as a powerful means in structural biology, is faced with challenges as applied to asymmetric proteins smaller than megadaltons due to low contrast. Zernike phase plate can improve the contrast by restoring the microscope contrast transfer function. Here, by exploiting simulated Zernike and conventional defocused cryoelectron microscope images with noise characteristics comparable to those of experimental data, we quantified the efficiencies of the steps in single particle analysis of ice-embedded RNA polymerase II (500 kDa), transferrin receptor complex (290 kDa), and T7 RNA polymerase lysozyme (100 kDa). Our results show Zernike phase plate imaging is more effective as to particle identification and also sorting of orientations, conformations, and compositions. Moreover, our analysis on image alignment indicates that Zernike phase plate can, in principle, reduce the number of particles required to attain near atomic resolution by 10-100 fold for proteins between 100 kDa and 500 kDa.

Alteration of hepatitis A virus (HAV) particles by a soluble form of HAV cellular receptor 1 containing the immunoglobin-and mucin-like regions.

Hepatitis A virus (HAV) infects African green monkey kidney cells via HAV cellular receptor 1 (havcr-1). The ectodomain of havcr-1 contains an N-terminal cysteine-rich immunoglobin-like region (D1), followed by a mucin-like region that extends D1 well above the cell surface. D1 is required for binding of HAV, and a soluble construct containing D1 fused to the hinge and Fc portions of human immunoglobin G1 (IgG1), D1-Fc, bound and neutralized HAV inefficiently. However, D1-Fc did not alter the virions. To determine whether additional regions of havcr-1 are required to trigger uncoating of HAV, we constructed D1muc-Fc containing D1 and two-thirds of the mucin-like region fused to the Fc and hinge portions of human IgG1. D1muc-Fc neutralized 10 times more HAV than did D1-Fc. Sedimentation analysis in sucrose gradients showed that treatment of HAV with 20 to 200 nM D1muc-Fc disrupted the majority of the virions, whereas treatment with 2 nM D1muc-Fc had no effect on the sedimentation of the particles. Treatment of HAV with 100 nM D1muc-Fc resulted in low-level accumulation of 100- to 125S particles. Negative-stain electron microscopy analysis revealed that the 100- to 125S particles had the characteristics of disrupted virions, such as internal staining and diffuse edges. Quantitative PCR analysis showed that the 100- to 125S particles contained viral RNA. These results indicate that D1 and the mucin-like region of havcr-1 are required to induce conformational changes leading to HAV uncoating.