Root volume measurements of maxillary canines and lateral incisors in patients with unilateral maxillary canine impaction.

OBJECTIVE: This study aimed to assess root volumes of maxillary canines and adjacent lateral incisors in patients with unilateral maxillary canine impaction. METHODS: This cross-sectional study was performed on cone-beam computed tomography (CBCT) scans of 100 patients (49 females and 51 males) with unilateral maxillary canine impaction. The images were loaded in Planmeca Romexis Viewer, and root layers between the cementoenamel junction and apex were reconstructed at 600-µm intervals. At each layer, the root boundary was marked, and finally, the root volume was calculated by multiplying the layers' area by the thickness of 600 µm. The root size of canines and lateral incisors was compared between the impaction and normal eruption sides. RESULTS: Sixty-two patients showed buccal canine impaction, and 38 presented palatal impaction. The mean root volume of canines on the impaction side was significantly greater than that on the normal eruption side; either the tooth was buccally or palatally impacted (p<0.001). The lateral incisors on the side of buccally-impacted canines showed a significantly smaller root volume than that of the contralateral side (p<0.001). However, there was no significant difference in the root size of lateral incisors between the two sides in cases presenting palatal canine impaction (p=0.177). CONCLUSION: The difference in root volume of canines between the two sides can serve as an indicator of canine impaction. The reduction in the root size of the lateral incisor on the side of the buccally impacted canine may be due to root resorption created by pressure from the canine's crown.

In silico Validation of Pseudomonas aeruginosa Exotoxin A Domain I Interaction with the Novel Human scFv Antibody.

BACKGROUND: Pseudomonas (P.) aeruginosa is one of the leading causes of nosocomial infections. The pathogenicity of P. aeruginosa is related to its inherent antimicrobial resistance and the diverse virulence factors of this bacterium. Owing to the specific role of exotoxin A in P. aeruginosa pathogenesis, it is known as a promising therapeutic candidate to develop antibodies as an alternative to antibiotics. OBJECTIVE: The present study aimed to validate the interaction between a single-chain fragment variable (scFv) antibody identified from an scFv phage library against domain I exotoxin A by bioinformatic tools. METHODS: For this, several bioinformatics tools, including Ligplot, Swiss PDB viewer (SPDBV), PyMOL, I-TASSER, Gromacs, and ClusPro servers were used to evaluate the interaction of scFv antibody with P. aeruginosa exotoxin A. The I-TASSER server was utilized to predict the function and structure of proteins. The interaction of two proteins was analyzed using ClusPro tools. The best docking results were further analyzed with Ligplot, Swiss PDB viewer, and PyMOL. Consequently, molecular dynamics simulation was utilized to predict the stability of the secondary structure of the antibody and the binding energy of the scFv antibody to the domain I of exotoxin A. RESULTS: As a result, we demonstrated that data from computational biology could provide proteinprotein interaction information between scFv antibody/domain I exotoxin A and offers new insights into antibody development and therapeutic expansion. CONCLUSION: In summary, a recombinant human scFv capable of neutralizing P. aeruginosa exotoxin A is recommended as a promising treatment for infections caused by P. aeruginosa.

Isolation and characterizations of a novel recombinant scFv antibody against exotoxin A of Pseudomonas aeruginosa.

BACKGROUND: Pseudomonas aeruginosa is the leading cause of nosocomial infections, especially in people with a compromised immune system. Targeting virulence factors by neutralizing antibodies is a novel paradigm for the treatment of antibiotic-resistant pseudomonas infections. In this respect, exotoxin A is one of the most potent virulence factors in P. aeruginosa. The present study was carried out to identify a novel human scFv antibody against the P. aeruginosa exotoxin A domain I (ExoA-DI) from a human scFv phage library. METHODS: The recombinant ExoA-DI of P. aeruginosa was expressed in E. coli, purified by Ni-NTA column, and used for screening of human antibody phage library. A novel screening procedure was conducted to prevent the elimination of rare specific clones. The phage clone with high reactivity was evaluated by ELISA and western blot. RESULTS: Based on the results of polyclonal phage ELISA, the fifth round of biopanning leads to the isolation of several ExoA-DI reactive clones. One positive clone with high affinity was selected by monoclonal phage ELISA and used for antibody expression. The purified scFv showed high reactivity with the recombinant domain I and full-length native exotoxin A. CONCLUSIONS: The purified anti-exotoxin A scFv displayed high specificity against exotoxin A. The human scFv identified in this study could be the groundwork for developing a novel therapeutic agent to control P. aeruginosa infections.