Preventing bisphosphonate induced osteonecrosis of the jaw with a polyguanidine conjugate (GuaDex): A promising new approach.

Osteonecrosis of the jaw (ONJ) is a relatively rare side effect after prolonged use of bisphosphonates, which are drugs used to treat bone resorption in osteoporosis and certain cancers. This study introduces a novel ONJ model in rats by combining exposure to bisphosphonates, oral surgery, and bacterial inoculation. Potential ONJ preventive effects of polyguanidine (GuaDex) or antibiotics were evaluated. The study consisted of twenty-four male Wistar rats were divided into four groups. Groups 1 to 3 were given weekly doses of i.v. Zoledronic acid (ZA), four weeks before and two weeks after an osteotomy procedure on their left mandibular first molar. Group 4 was a negative control. Streptococcus gordonii bacteria were introduced into the osteotomy pulp chamber and via the food for seven days. On day eight, the rats were given different treatments. Group 1 was given a GuaDex injection into the osteotomy socket, Group 2 was given an intramuscular (i.m.) injection of clindamycin, Group 3 (positive control) was given an i.m. injection of saline, and Group 4 was given an i.m. injection of saline. Blood samples were taken two weeks after the osteotomy procedure, after which the rats were euthanized. Bone healing, bone mineral density, histology, and blood status were analyzed. The results showed that Group 1 (GuaDex) had no ONJ, extensive ongoing bone regeneration, active healing activity, vascularization, and no presence of bacteria. Group 2 (clindamycin) showed early stages of ONJ, avascular areas, and bacteria. Group 3 showed stages of ONJ, inflammatory infiltrates, defective healing, and bacterial presence, and Group 4 had normal healing activity and no bacterial presence. Conclusion: ZA treatment and bacterial inoculation after tooth extraction inhibited bone remodeling/healing and induced ONJ characteristic lesions in the rats. Only GuaDex apparently prevented ONJ development, stimulated bone remodeling, and provided an antimicrobial effect.

Gene expression profiles of breast cancer metastasis according to organ site.

In advanced breast cancer, biomarker identification and patient selection using a metastatic tumor biopsy is becoming more necessary. However, the biology of metastasis according to the organ site is largely unknown. Here, we evaluated the expression of 771 genes in 184 metastatic samples across 11 organs, including liver, lung, brain, and bone, and made the following observations. First, all PAM50 molecular intrinsic subtypes were represented across organs and within immunohistochemistry-based groups. Second, HER2-low disease was identified across all organ sites, including bone, and HER2 expression significantly correlated with ERBB2 expression. Third, the majority of expression variation was explained by intrinsic subtype and not organ of metastasis. Fourth, subtypes and individual subtype-related genes/signatures were significantly associated with overall survival. Fifth, we identified 74 genes whose expression was organ-specific and subtype-independent. Finally, immune profiles were found more expressed in lung compared to brain or liver metastasis. Our results suggest that relevant tumor biology can be captured in metastatic tissues across a variety of organ sites; however, unique biological features according to organ site were also identified and future studies should explore their implications in diagnostic and therapeutic interventions.

Mandibular condyle fractures: A diagnosis with controversial treatment.

BACKGROUND: Over the years, the treatment to be chosen for the resolution of condylar fractures has been discussed with great concern. Treatment depends on the type and location of the fracture, as well as other associated factors such as facial injuries and concurrent diseases. AIM OF THE STUDY: The aim of the study was to make a review of the different criteria to establish a diagnosis and treatment to resolve mandibular condyle fractures, according to the evolution of the years and what this entails. DISCUSSION: Management of condylar fractures remains controversial among surgeons. However, as time goes by and as comparative and analytical studies are carried out within the issue, parameters and criteria are established to facilitate the decisions taken regarding the management and treatment of condylar fractures. CONCLUSION: Condylar fractures must be managed according to the clinical and case presentation.

ANTECEDENTES: A lo largo de los años se ha discutido con gran preocupación el tratamiento que hay que escoger para la resolución de las fracturas condilares. Este depende del tipo y la localización de la fractura, así como de otros factores asociados, como las lesiones faciales y las enfermedades concomitantes. OBJETIVO: Hacer una revisión de los diferentes criterios para establecer un diagnóstico y un tratamiento para la resolución de las fracturas del cóndilo mandibular, de acuerdo con la evolución de los años y lo que esto conlleva. DISCUSIÓN: El manejo de las fracturas condilares sigue siendo controvertido entre los cirujanos. Sin embargo, a medida que pasa el tiempo y se realizan estudios comparativos y analíticos sobre el tema, se establecen parámetros y criterios para facilitar las decisiones tomadas en relación con el manejo y el tratamiento de las fracturas condilares. CONCLUSIÓN: Las fracturas condilares deben ser manejadas según la clínica y la presentación del caso.

Estudio comparativo entre ibuprofeno dexametasona y betametasona en el control postoperatorio en cirugía de terceros molares retenidos / A comparative study between dexamethasone ibuprofen and betamethasone for the control of postoperative swelling after impacted third molars surgery

Se realizó un estudio doble ciego con 60 pacientes que fueron sometidos a la remoción de terceros molares retenidos clase II, administrándoles tres fármacos diferentes para el control del edema postoperatorio, siendo evaluados por medio de puntos anatómicos faciales a las 24, 48 y 72 horas, así como al quinto y décimo día del postoperatorio