Regeneration of lingual musculature in rats using myoblasts over porcine bladder acellular matrix.

OBJECTIVES: To use tissue engineering muscle repair (TEMR) for regenerating the lingual musculature of hemiglossectomized rats using neonatal myoblasts (NM) on porcine acellular urinary bladder matrix (AUBM). MATERIAL AND METHODS: The study used 80 male rats. A volumetric muscle loss (VML) injury was created on the left side of the tongue. The rats were randomized into four groups: Group 1 (AUBM + myoblasts); Group 2 (AUBM); Group 3 (myoblasts); and Group 4 (control). NM were obtained from neonatal rats. The animals were weighed on day 0 and just before euthanasia. Five rats in each group were euthanized at days 2, 14, 28, and 42; the tongues were prepared for morphometric analysis, postoperative left hemitongue weight, and immunohistochemical analysis (desmin, CD-31, and anti-neurofilament). RESULTS: The weight gain from greatest to least was as follows: AUBM + myoblasts > myoblasts > AUBM > control. The tongue dorsum occupied by VML, and difference in mg between control side and intervened side from least to great was as follows: AUBM + myoblasts < myoblasts < AUBM < control. The order from highest to lowest antibody positivity was as follows: AUBM + myoblasts > myoblasts > AUBM > control. CONCLUSION: The use of porcine AUBM and NM for the regeneration of lingual musculature was found to be an effective TEMR treatment for repairing tongue VML injury.

Histological and immunohistochemical soft-tissue response to cylindrical and concave abutments: Multicenter randomized clinical trial.

BACKGROUND: This study aimed to analyze the influence of concave and cylindrical abutments on peri-implant soft tissue. Dimensions, collagen fiber orientation, and immunohistochemical data were assessed. METHODS: A multicenter, split-mouth, double-blind randomized clinical trial was conducted. Two groups were analyzed: cylindrical abutments and concave abutments. After a 12-week healing period, peri-implant soft tissue samples were collected, processed, and evaluated for dimensions, collagen fiber orientation, and immunohistochemical data. Inflammatory infiltration and vascularization were assessed, and the abutment surfaces were analyzed using scanning electron microscopy. The statistical analysis was performed using the SPSS version 20.0 statistical package. RESULTS: A total of 74 samples in 37 patients were evaluated. Histological evaluation of peri-implant soft tissue dimensions revealed significant differences between concave and cylindrical abutments. Concave abutments exhibited greater total height (concave: 3.57 ± 0.28 - cylindrical: 2.95 ± 0.27) and barrier epithelium extension (concave: 2.46 ± 0.17 - cylindrical: 1.89 ± 0.21) (p < 0.05), while the supracrestal connective tissue extension (concave: 1.11 ± 0.17 - cylindrical: 1.03 ± 0.16) was slightly greater (p > 0.05). Collagen fiber orientation favored concave abutments (23.76 ± 5.86), with significantly more transverse/perpendicular fibers than for cylindrical abutments (15.68 ± 4.57). The immunohistochemical analysis evidenced greater inflammatory and vascular intensity in the lower portion for both abutments, though concave abutments showed lower overall intensity (concave: 1.05 ± 0.78 - cylindrical: 1.97 ± 0.68) (p < 0.05). The abutment surface analysis demonstrated a higher percentage of tissue remnants on concave abutments (42.47 ± 1.32; 45.12 ± 3.03) (p < 0.05). CONCLUSIONS: Within the limitations of this study, concave abutments presented significantly greater peri-implant tissue height, linked to an extended barrier epithelium, versus cylindrical abutments in thick tissue phenotype. This enhanced soft tissue sealing, favoring a greater percentage of transversely oriented collagen fibers. The concave design reduced chronic inflammatory exudation with T and B cells, thus minimizing the risk of chronic inflammation. PLAIN LANGUAGE SUMMARY: This study looked at how 2 different shapes of dental implant abutments (the parts that connect the implant to the crown), specifically concave and cylindrical, affect the soft tissue around the implants. We wanted to see how these shapes influenced the tissue's size, structure, and health. We conducted a clinical trial with 37 patients, comparing the 2 types of abutments in the same mouth over 12 weeks. Our findings showed that the concave abutments led to a taller and more extensive layer of protective tissue around the implant compared to the cylindrical ones. This protective tissue had more favorable collagen fiber orientation, which is important for the strength and health of the tissue. Additionally, the concave abutments resulted in less inflammation and better tissue integration. In conclusion, concave abutments may provide better support and health for the soft tissue around dental implants, reducing the risk of chronic inflammation and potentially leading to better long-term outcomes for patients with dental implants.

Effect of Female Sex Hormones on the Immune Response against Chlamydia abortus and on Protection Conferred by an Inactivated Experimental Vaccine in a Mouse Model.

Mice are valuable models extensively used to test vaccine candidates against Chlamydia abortus and to clarify immunopathological mechanisms of the bacteria. As this pathogen has the ability to reactivate during pregnancy, it is important to deepen the knowledge and understanding of some of the effects of female hormones on immunity and vaccination. This study is aimed at describing the role of sex hormones in the pathology of OEA during chlamydial clearance using ovariectomised mice and also gaining an understanding of how 17ß-oestradiol or progesterone may impact the effectiveness of vaccination. Animals were treated with sex hormones and infected with C. abortus, and the kinetics of infection and immune response were analysed by means of bacterial isolation, histopathology, and immunohistochemistry. In a second phase of the study, protection conferred by an experimental vaccine after hormone treatment was assessed. Oestradiol showed a stimulatory effect on the immune response during infection, with a more efficient recruitment of macrophages and T-cells at the infection site. Furthermore, after vaccination, oestradiol-treated animals showed a stronger protection against infection, indicating that this hormone has a positive effect, stimulating a specific memory response to the pathogen.