Relationship of the Morphology and Size of Sella Turcica with Dental Anomalies and Skeletal Malocclusions

This study aimed to assess the relationship of the morphology and size of the sella turcica (ST) with dental anomalies and skeletal malocclusions. This cross-sectional study was conducted on records of fixed orthodontic patients treated between 2013 and 2022. Cephalometric analysis was performed to determine the anteroposterior and vertical skeletal patterns. Preoperative panoramic radiographs and lateral cephalograms, intraoral photographs, and primary dental casts of patients were used to detect dental anomalies. Gender, sagittal and vertical skeletal patterns, dental anomalies, and dimensions (length, depth, and diameter), and morphology of the ST were all recorded according to the lateral cephalograms of patients. Data were analyzed using independent t-test, one-way and two-way ANOVA, Chi-square test, and log rank test (alpha = 0.05). The depth and diameter of the ST had no significant correlation with gender (p > 0.05); however, the length of the ST was significantly longer in males than females (p < 0.05). The morphology of the ST had a significant correlation with gender (p < 0.05). The ST morphology had a significant correlation with the anteroposterior skeletal pattern, microdontia, and tooth impaction as well (p < 0.05). The present results revealed a significant correlation of the ST morphology with the anteroposterior skeletal pattern, microdontia, and tooth impaction.

Relationship between Posterior Permanent Dentition Pattern and Radiographic Changes of the Mandibular Condyle

This study assessed the relationship between posterior permanent dentition and radiographic changes of the mandibular condyle. This descriptive, cross-sectional study was conducted on 300 panoramic radiographs of patients over 40 years of age (188 females and 112 males). Panoramic radiographs were evaluated for condylar changes such as flattening, subcortical sclerosis, subcortical cyst, erosion, osteophytes, and generalized sclerosis. Presence of muscle pain and temporomandibular joint (TMJ) pain and sounds, and history of TMJ trauma were also assessed. The occlusal scheme of posterior teeth was analyzed according to the Eichner's index. The frequency of condylar changes was calculated in the right and left sides, and their association with posterior permanent dentition was analyzed by the Chi-square test (alpha = 0.05). The frequency of flattening, muscle pain, TMJ sounds, and erosion was 11.7%, 9.7%, 5.7%, and 3.7% in the right side, respectively. The frequency of flattening, muscle pain, erosion, and subcortical cyst was 12%, 9.3%, 5%, and 5% in the left side, respectively. The frequency of bilateral muscle pain, flattening, TMJ sounds, and TMJ pain was 18%, 16.7%, 11.7%, and 9.3%, respectively. Cases with TMJ trauma, generalized sclerosis, and osteophytes were few. According to the Eichner's index, most patients with condylar changes had classes A and B, and a smaller percentage had class C. No significant difference was noted between healthy individuals and those with condylar changes regarding dentition patterns. No relationship existed between condylar changes and posterior permanent dentition pattern.

A dual-signaling electrochemical ratiometric strategy combining "signal-off" and "signal-on" approaches for detection of MicroRNAs

A dual-signaling electrochemical ratio metric strategy was developed for detection microRNA-18a based on the duplex-specific nuclease-assisted target recycling and electrochemical atom transfer radical polymerization signal amplification. In the presence of target microRNA, RNA/DNA duplexes are formed, which become the substrate of the duplex-specific nuclease-assisted target recycling. Hence only the DNA strand is cleaved by duplex-specific nuclease enzyme, resulting in the throw away of methylene blue (MB) from the electrode (signal off) accompanied by releasing of target microRNA, which can be recycled in the next hybridization. The remaining piece of capture DNAs on the electrode surface hybridize with the Azide labeled-signal DNAs. "Click reactions" were carried out between 3-Butynyl-2-bromoisobutyrate and Azide to initiate the electrochemical atom transfer radical polymerization reaction. This process could bring a great number of ferrocenylmethyl methacrylate (FMMA) on the surface of electrode (signal on). The I_FMMA/I_MB value was proportionate to the microRNA-18a concentration and measured by square wave voltammetry. The promising potential of the proposed biosensor in clinical analyses was exhibited by its remarkable features such as strong performance, high specificity, agreeable storage stability, and notable selectivity in real sample evaluation with no pretreatment or amplification. Finally, our biosensing method offers such an application to be used for the early clinical diagnosis of Pancreatic Cancer.

[Tumor escape mechanism involving Fas and Fas-L molecules in human colorectal tumors]

OBJECTIVES

The interaction between Fas and its ligand (Fas-L) leads to Fas-positive cell apoptosis. Our objective was to study a new mechanism of tumor escape involving these molecules, the so-called "counterattack".

METHODS

We used flow cytometry to analyze Fas expression and apoptosis sensitivity in different human colorectal tumor cell lines. The presence of Fas-L mRNA was analyzed by RT-PCR. We studied apoptosis rate in peripheral blood lymphocytes and lymph node lymphocytes from patients with colorectal cancer by flow cytometric cell cycle analysis after in vitro culture with or without tumor cells.

RESULTS

We found differences in Fas expression and sensitivity to Fas-induced apoptosis between different colorectal tumor cell lines. Interferon-gamma was also found to affect Fas expression and apoptosis sensitivity induced by an anti-Fas antibody. Actinomycin-D decreased Fas expression and apoptosis sensitivity in certain cell lines. Our data confirmed the tumor cell "counterattack" hypothesis by showing their capacity to induce apoptosis in lymphocytes from patients with colorectal cancer.

CONCLUSION

Fas expression and apoptosis sensitivity in colorectal tumor cell lines can be modulated by actinomycin-D or interferon-gamma. These data may suggest new therapeutic options based on increased Fas expression in tumor cells induced by interferon-gamma, or on apoptosis induction in tumor cells with a local intratumoral treatment with actinomycin-D.